diff --git a/docs/audits/architecture_a_m.json b/docs/audits/architecture_a_m.json
index 2de6bf56fc..a4e273211a 100644
--- a/docs/audits/architecture_a_m.json
+++ b/docs/audits/architecture_a_m.json
@@ -168,7 +168,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares AnalysisConsolidationConfig and its standalone consolidation policy."
       },
       {
@@ -178,7 +178,7 @@
       },
       {
         "path": "tests/unit/test_function_artifact_materialization.py",
-        "sha256": "4ae063cac0f93a03b5b4aab7304c8d7e6bcfc04ec74d107ea14c94f76be755ca",
+        "sha256": "ba4f8f5f165ab87c3000d6d371a6f25cf4ec6a5d39b5047abaa392c827fe9ae8",
         "role": "Proves consolidation consumes runtime CSV values, uses the compiled backend destination, ignores non-table artifacts, and propagates failures."
       },
       {
@@ -188,7 +188,7 @@
       },
       {
         "path": "openhcs/processing/materialization/core.py",
-        "sha256": "1372625f3d7dc04cf6822a1887871dfa9a149b2313df7d7acefd452a6ad0f932",
+        "sha256": "1f5a89a1eb50766ef093df3fece16d6bb03422b92d062fe8ae6471656b1ebd45",
         "role": "Owns writer runtime-path selection before rendering and the shared ROI target request."
       }
     ],
@@ -675,7 +675,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares OpenHCS domain configuration that consumes ObjectState mechanics."
       }
     ],
@@ -841,7 +841,7 @@
       },
       {
         "path": "openhcs/core/context/processing_context.py",
-        "sha256": "9384fcc4d5ed7ea8607257ec448958f85a88a5caa6ae06f22142cc51b58b479e",
+        "sha256": "c7b79f50661c528261ce8c577fd67c753c84a5e499aa87cd5e540b53417351a2",
         "role": "Owns the compiled multiprocessing-axis identity for one processing context."
       },
       {
@@ -912,7 +912,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the OpenHCS global, pipeline, step, and standalone configuration hierarchy."
       }
     ],
@@ -1142,7 +1142,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares standalone ExperimentalAnalysisConfig options and all directory-workflow filenames."
       },
       {
@@ -1198,7 +1198,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Pins the eight first-party package constraints and documents their installed integration surface."
       },
       {
@@ -1805,7 +1805,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the WellFilterConfig family preview policy and WellFilterMode member operators."
       },
       {
@@ -1955,7 +1955,7 @@
       },
       {
         "path": "tests/unit/test_config_document.py",
-        "sha256": "c6b291080398669b8449cb6ddaa78350f6c5b09f4f0cc57ebe92ac5f32460915",
+        "sha256": "0ee12db4633ab39b34f630e4ee1b0c48b40d8226f91fddc504bb3311b9612cda",
         "role": "Proves explicit, defaulted, and invalid typed field projections from canonical configuration source."
       },
       {
diff --git a/docs/audits/architecture_n_z_development.json b/docs/audits/architecture_n_z_development.json
index 55003c0404..78b0415766 100644
--- a/docs/audits/architecture_n_z_development.json
+++ b/docs/audits/architecture_n_z_development.json
@@ -220,7 +220,7 @@
       },
       {
         "path": "openhcs/core/orchestrator/orchestrator.py",
-        "sha256": "ca733be328ed5f1f033ee521fbf9bf0b088791bd19542f0071ddb01b4f2d3d9c",
+        "sha256": "843e994d7b16592f43a15ce36c33a51ead534cf22df792838ce2b800621114b7",
         "role": "PipelineOrchestrator configuration ownership, resolution, compiler setup, and executor lifecycle."
       },
       {
@@ -250,7 +250,7 @@
       },
       {
         "path": "openhcs/core/context/processing_context.py",
-        "sha256": "9384fcc4d5ed7ea8607257ec448958f85a88a5caa6ae06f22142cc51b58b479e",
+        "sha256": "c7b79f50661c528261ce8c577fd67c753c84a5e499aa87cd5e540b53417351a2",
         "role": "Owns explicit release of the context-local image-stack cache without discarding observations."
       },
       {
@@ -290,7 +290,7 @@
     "authority": [
       {
         "path": "openhcs/core/orchestrator/orchestrator.py",
-        "sha256": "ca733be328ed5f1f033ee521fbf9bf0b088791bd19542f0071ddb01b4f2d3d9c",
+        "sha256": "843e994d7b16592f43a15ce36c33a51ead534cf22df792838ce2b800621114b7",
         "role": "PipelineOrchestrator configuration ownership, resolution, compiler setup, and executor lifecycle."
       },
       {
@@ -512,7 +512,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Pipeline, global, step, processing, and source configuration declarations."
       },
       {
@@ -572,7 +572,7 @@
       },
       {
         "path": "openhcs/core/context/processing_context.py",
-        "sha256": "9384fcc4d5ed7ea8607257ec448958f85a88a5caa6ae06f22142cc51b58b479e",
+        "sha256": "c7b79f50661c528261ce8c577fd67c753c84a5e499aa87cd5e540b53417351a2",
         "role": "Owns the compiled multiprocessing-axis identity carried by each runtime context."
       },
       {
@@ -822,7 +822,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Pipeline, global, step, processing, and source configuration declarations."
       },
       {
@@ -1020,7 +1020,7 @@
       },
       {
         "path": "openhcs/processing/materialization/core.py",
-        "sha256": "1372625f3d7dc04cf6822a1887871dfa9a149b2313df7d7acefd452a6ad0f932",
+        "sha256": "1f5a89a1eb50766ef093df3fece16d6bb03422b92d062fe8ae6471656b1ebd45",
         "role": "Nominal artifact materialisation and ROI projection strategies."
       },
       {
@@ -1408,7 +1408,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       }
     ],
@@ -1646,7 +1646,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       },
       {
@@ -1719,7 +1719,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package-discovery, and installed entry-point authority."
       },
       {
@@ -2612,7 +2612,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns nominal gallery scenario identity, publication targets, representative images, copy, accessibility text, dimensions, contextual and stable-window capture targets, and derivative contracts."
       },
       {
@@ -2659,7 +2659,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       },
       {
@@ -2763,7 +2763,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       },
       {
@@ -2811,7 +2811,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       },
       {
@@ -2869,7 +2869,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the nominal gallery scenario lattice, stable-window and contextual capture targets, publication targets, derivative inventory, source evidence, card rendering, and generated release record."
       },
       {
@@ -3521,7 +3521,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       },
       {
@@ -3712,7 +3712,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Current Python support, dependency, package discovery, and entry-point authority."
       }
     ],
diff --git a/docs/audits/pr129_tiff_compression_review_20260924.md b/docs/audits/pr129_tiff_compression_review_20260924.md
new file mode 100644
index 0000000000..a38b161206
--- /dev/null
+++ b/docs/audits/pr129_tiff_compression_review_20260924.md
@@ -0,0 +1,55 @@
+# PR #129 TIFF compression authority-delta review
+
+Date: 2026-09-24
+
+The opt-in disk-TIFF writer change invalidated 34 recorded authority edges
+across 29 active documentation pages. I re-read each complete dependent page
+against the changed OpenHCS declarations, runtime path, and tests, and the
+PolyStore codec declaration. The generated configuration reference remains the
+authority for exact fields, accepted values, and defaults; it is not duplicated
+as a hand-maintained field table.
+
+Two pages needed prose changes. `concepts/storage_system.rst` now explains the
+separation of disk TIFF compression from Zarr compression and semantic
+materialization. `guide_for_biologists/configuration_reference.rst` now names
+the `TiffConfig` family and its scope in the practitioner mental model. Both
+remain explanations rather than becoming exhaustive field references. The
+other 27 pages retain their existing claims and Diátaxis purposes: the new
+config is resolved from the existing pipeline declaration, carried in the
+compiled processing context, and used only on disk TIFF writes, so their
+descriptions of inheritance, runtime ownership, ROI, MCP schema projection,
+analysis, and viewer behavior remain accurate.
+
+This is an editorial receipt, not product authority. The authoritative files
+are the declarations, implementations, and tests recorded in the JSON audit
+entries. The changed page and authority digests were refreshed only after this
+comparison. Documentation validation passed for 155 audited sources, the full
+Sphinx HTML build succeeded with warnings treated as errors, and 15 focused
+documentation, MCP, and TIFF-output tests passed. At this initial review,
+the separate published-dependency readiness gate remained open because the
+PolyStore change had not yet been released.
+
+The first CI pass found three Black-only formatting differences. After running
+the pinned formatter, the changed materialization owner files differ only in
+line wrapping. I rechecked the complete analysis-consolidation, ROI, and storage
+pages against those unchanged semantics before refreshing their three affected
+authority digests. The reformatted test file is not a recorded audit authority.
+
+## Published-dependency follow-up
+
+PolyStore PR #11 was merged and released as v0.2.19. Its publish workflow
+passed, and both the wheel and source distribution are present on PyPI.
+OpenHCS now requires `polystore>=0.2.19,<0.3` and pins the PolyStore
+submodule to release commit `0efe67fdd14985bf90cee6e0f0c4735d41d265d1`.
+The 17 documentation audit entries that depend on `pyproject.toml` were
+rechecked against the new dependency floor and their authority digests
+refreshed. No affected explanatory page asserted the prior floor.
+
+The subsequent website CI run exposed an eager import in the gallery catalog:
+its source-capture request used `ExecutionConnectionSpec` only as a postponed
+type annotation, but importing that DTO loaded the scientific runtime into
+the deliberately minimal website environment. The import is now restricted to
+type checking. The gallery's runtime declarations, capture behavior, and
+published projections are unchanged. The 13 audited pages referencing the
+gallery catalog were checked for claims about those surfaces, and their
+authority digests were refreshed.
diff --git a/docs/audits/project_surface.json b/docs/audits/project_surface.json
index 5f0ca69728..ab29a11a7f 100644
--- a/docs/audits/project_surface.json
+++ b/docs/audits/project_surface.json
@@ -12,7 +12,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the published README, Python range, package dependencies, optional surfaces, console commands, and project links."
       },
       {
diff --git a/docs/audits/user_docs.json b/docs/audits/user_docs.json
index cf587ac4db..79b610ca7a 100644
--- a/docs/audits/user_docs.json
+++ b/docs/audits/user_docs.json
@@ -11,7 +11,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -21,7 +21,7 @@
       },
       {
         "path": "openhcs/core/orchestrator/orchestrator.py",
-        "sha256": "ca733be328ed5f1f033ee521fbf9bf0b088791bd19542f0071ddb01b4f2d3d9c",
+        "sha256": "843e994d7b16592f43a15ce36c33a51ead534cf22df792838ce2b800621114b7",
         "role": "Owns execution orchestration, worker submission, progress handling, and cleanup of compiled bundles."
       },
       {
@@ -171,7 +171,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       },
       {
@@ -495,7 +495,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -674,7 +674,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -707,7 +707,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       },
       {
@@ -727,7 +727,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -843,7 +843,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -871,7 +871,7 @@
   },
   {
     "path": "docs/source/concepts/storage_system.rst",
-    "source_sha256": "fa377aa5280583609ca43d6190cc03aaabb1a7abed40dd4344d8e686866ce1f7",
+    "source_sha256": "6457c0c132bd45f195274e51b255f45713b5efda9ee7ada352de556ac4aa1dde",
     "audience": [
       "pipeline authors",
       "storage integrators"
@@ -881,7 +881,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -891,7 +891,7 @@
       },
       {
         "path": "openhcs/core/steps/function_artifact_materialization.py",
-        "sha256": "5a219f74d1abfd59f915aae06cb3dc2befa1d1a83b82b59d6a8f98f3ac5865ba",
+        "sha256": "18c809a2d511501c4e308f6e92c18d5bb59744d4d3f59bb2bfc2507f2a2bdd03",
         "role": "Owns the rules that materialise function outputs through the configured storage backend."
       },
       {
@@ -899,14 +899,37 @@
         "sha256": "ae641affae21b61448816a14bd68b7f2f3fc0082f0f1fbe51079ed32520450b1",
         "role": "Declares the storage backend interface and lifecycle shared by local and remote materialisation backends."
       },
+      {
+        "path": "external/PolyStore/src/polystore/config.py",
+        "sha256": "62c8acad3da3abed8ccf7f1166fc6a0d094be1c3e842cec6446780541df292a0",
+        "role": "Declares lossless disk-TIFF codec settings, defaults, and path-specific batching."
+      },
+      {
+        "path": "external/PolyStore/src/polystore/disk.py",
+        "sha256": "cf089b8c79f86099a7cea1b6cbe43ceaec6331196a44b43183f2e64b7746c219",
+        "role": "Applies TIFF codec settings in the disk writer without changing other formats."
+      },
+      {
+        "path": "external/arraybridge/src/arraybridge/decorators.py",
+        "sha256": "99823105b0ae59054df1d84013633b8b6628d0a6dc3326383199ac7c65c69bed",
+        "role": "Applies declared dtype conversion to a callable result before materialisation can persist it."
+      },
       {
         "path": "tests/unit/test_runtime_value_store.py",
         "sha256": "8900a7b83b59d0a40f9698dbafaaba778df982f9d7a0b628f80eab97335aeab0",
         "role": "Proves scoped typed runtime-value insertion, lookup, isolation, and cleanup."
+      },
+      {
+        "path": "tests/unit/test_tiff_output_compression.py",
+        "sha256": "458f576e545a033ed9e23b9dc349ab92c19d296ec7f0e269ea89884cd9b82942",
+        "role": "Proves configured main-flow and named-artifact disk-TIFF writes round-trip exactly."
       }
     ],
-    "findings": [],
-    "disposition": "keep",
+    "findings": [
+      "The storage explanation did not distinguish optional disk-TIFF compression from Zarr compression or semantic materialization.",
+      "The compression explanation did not contrast lossless codec selection with the existing value-changing callable dtype policy."
+    ],
+    "disposition": "revise",
     "validation": [
       "Re-read docs/source/concepts/storage_system.rst in full against repository base bb4218fae and the current shared worktree; challenged its explanation user need for accuracy, freshness, duplication, owner boundaries, flow, and navigation.",
       "Compared every factual claim directly with the current hash-pinned authorities: openhcs/core/config.py; openhcs/core/runtime_stores.py; openhcs/core/steps/function_artifact_materialization.py; external/PolyStore/src/polystore/base.py; tests/unit/test_runtime_value_store.py.",
@@ -917,7 +940,9 @@
       "2026-09-09: Re-read this page against the changed source authorities for release 0.8.3; retained its Diataxis purpose and updated affected workflow claims.",
       "2026-09-16: Re-read the complete explanation against runtime artifact materialization changes. Added the semantic-versus-filename identity boundary and confirmed that path completion does not mutate artifact metadata; 249 focused materialization and adjacent runtime tests passed.",
       "2026-09-22 PR #126 targeted authority-delta review: re-read the complete page against `openhcs/core/config.py`; retained the supported claims, findings, and disposition, then refreshed only these compared evidence hashes. Review scope and the separate blocking runtime evidence are recorded in `docs/audits/pr126_authority_delta_review_20260922.md`.",
-      "2026-09-22 PR #126 integrated-repair follow-up: re-read the complete page and the final owner/test changes in `openhcs/core/steps/function_artifact_materialization.py`. Scalar image materialization now selects the execution scope matching the complete source address, deduplicates equivalent repeated group records, and rejects conflicts; the documented separation of semantic source identity, filename completion, runtime records, and persistence remains accurate. Refreshed only these compared evidence hashes; details are retained in `docs/audits/pr126_authority_delta_review_20260922.md`."
+      "2026-09-22 PR #126 integrated-repair follow-up: re-read the complete page and the final owner/test changes in `openhcs/core/steps/function_artifact_materialization.py`. Scalar image materialization now selects the execution scope matching the complete source address, deduplicates equivalent repeated group records, and rejects conflicts; the documented separation of semantic source identity, filename completion, runtime records, and persistence remains accurate. Refreshed only these compared evidence hashes; details are retained in `docs/audits/pr126_authority_delta_review_20260922.md`.",
+      "2026-09-24 PR #129: re-read the complete explanation against the changed config, materialization, PolyStore writer, and exact-roundtrip test authorities; added the disk-TIFF compression boundary without copying exact generated fields. Review scope is recorded in `docs/audits/pr129_tiff_compression_review_20260924.md`.",
+      "2026-09-24: re-read the complete explanation and checked the ArrayBridge dtype wrapper against the PolyStore TIFF writer; documented that the codec preserves the callable-produced dtype, while a callable-level conversion changes it before persistence."
     ]
   },
   {
@@ -932,7 +957,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       },
       {
@@ -1167,7 +1192,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled Function Selector capture declaration, accessibility text, capture target, and generated visual projection."
       },
       {
@@ -1264,7 +1289,7 @@
   },
   {
     "path": "docs/source/guide_for_biologists/configuration_reference.rst",
-    "source_sha256": "3a70946f59a595f5ebbdf4a176280d7ba497f630cec92c45cd2710d40a10f6f2",
+    "source_sha256": "ba3c4ef923c4f643c06accc8641c462b2f63a8e46694ef984dde96ef49a0d9c7",
     "audience": [
       "imaging scientists",
       "pipeline authors"
@@ -1274,7 +1299,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -1324,13 +1349,14 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled global, pipeline, step, and nested function configuration capture declarations, accessibility text, capture targets, and generated visual projections."
       }
     ],
     "findings": [
       "The configuration explanation now distinguishes source-document omission, which selects PipelineConfig(), from normal lazy-field inheritance.",
-      "The explanation did not tell agents that live field help projects accepted enum input strings, including member names for non-string values."
+      "The explanation did not tell agents that live field help projects accepted enum input strings, including member names for non-string values.",
+      "The practitioner configuration map did not name the new optional TIFF compression family or distinguish its output scope from Zarr and viewer streams."
     ],
     "disposition": "revise",
     "validation": [
@@ -1347,7 +1373,8 @@
       "2026-09-08: targeted 0.8.3 authority-delta review, retaining the earlier full-page review. Checked affected catalogue ownership, code round-trip, runtime-setting and endpoint lifecycle claims against the changed declarations. Updated the code-editing, dtype, callable-authoring and connection explanations where behaviour changed. Dependency and version changes do not alter the retained installation or package-ownership descriptions. Focused source/ObjectState round-trip and callable-contract checks passed 53 tests; this is not a new whole-document audit.",
       "2026-09-09: Re-read this page against the changed source authorities for release 0.8.3; retained its Diataxis purpose and updated affected workflow claims.",
       "2026-09-09: Reviewed the page sections affected by exact manager-item navigation, selection recovery guidance, and the pyqt-reactive dependency floor change from 0.3.20 to 0.3.21. Generic selection and deferred dispatch remain in pyqt-reactive; domain window identities stay in OpenHCS. Navigation acceptance does not replace action revision guards. Installation extras, Python support, code-document apply, and experimental/runtime semantics are unchanged by this batch. Updated the MCP architecture and basic-interface navigation explanations; retained existing setup/ownership links rather than duplicating a version catalogue. Only the reviewed navigation/dependency authorities were refreshed, excluding the scientific threshold patch. Final parent gates: 176 OpenHCS and 463 pyqt-reactive tests passed, including deferred target removal; full fresh-agent trial remains separate acceptance evidence.",
-      "2026-09-22 PR #126 targeted authority-delta review: re-read the complete page against `openhcs/core/config.py`, `tests/unit/pyqt_gui/test_ui_agent_bridge.py`; retained the supported claims, findings, and disposition, then refreshed only these compared evidence hashes. Review scope and the separate blocking runtime evidence are recorded in `docs/audits/pr126_authority_delta_review_20260922.md`."
+      "2026-09-22 PR #126 targeted authority-delta review: re-read the complete page against `openhcs/core/config.py`, `tests/unit/pyqt_gui/test_ui_agent_bridge.py`; retained the supported claims, findings, and disposition, then refreshed only these compared evidence hashes. Review scope and the separate blocking runtime evidence are recorded in `docs/audits/pr126_authority_delta_review_20260922.md`.",
+      "2026-09-24 PR #129: re-read the complete inheritance explanation against the new registered TIFF config and added its disk-output scope to the existing mental model; exact fields remain generated. Review scope is recorded in `docs/audits/pr129_tiff_compression_review_20260924.md`."
     ]
   },
   {
@@ -1461,7 +1488,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       }
     ],
@@ -1530,7 +1557,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled source-image browser capture, caption, accessibility text, dimensions, and source evidence."
       },
       {
@@ -1550,7 +1577,7 @@
       },
       {
         "path": "external/PolyStore/src/polystore/config.py",
-        "sha256": "241f728c991b9a4ac4d4440bba9bc08b5d89d23e7f8b3b9fcbdc18eb562a9bbc",
+        "sha256": "62c8acad3da3abed8ccf7f1166fc6a0d094be1c3e842cec6446780541df292a0",
         "role": "Owns the nominal Zarr compressor factories, Numcodecs creation, chunk strategy, and backend configuration."
       },
       {
@@ -1649,7 +1676,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       },
       {
@@ -1781,7 +1808,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled synthetic generator, plate metadata, and live measurement result capture declarations used by the first-workflow tutorial."
       }
     ],
@@ -2323,7 +2350,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Includes the complete openhcs/omero deployment and plugin bundle in installed distributions."
       },
       {
@@ -2805,7 +2832,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the landing-page workspace scenario, representative image, caption, description, alt text, dimensions, and release evidence."
       }
     ],
@@ -2836,7 +2863,7 @@
     "authority": [
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       },
       {
@@ -2903,7 +2930,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -3085,7 +3112,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -3130,7 +3157,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -3192,7 +3219,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Projects every registered stable-window identity into its documentation scenario, capture target, filename, and accessibility text."
       },
       {
@@ -3240,7 +3267,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -3369,7 +3396,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the lazy-inheritance scenario, representative poster, caption, description, alt text, dimensions, and release evidence."
       },
       {
@@ -3469,7 +3496,7 @@
       },
       {
         "path": "pyproject.toml",
-        "sha256": "61621859d0f780d2d3e004782f242ef923d6cd1e83bb3bbc9761197ba33a4165",
+        "sha256": "6217b5f029796edcd83aa47fb8632d37aa7552344755c578fa4f181a6b23282d",
         "role": "Declares the package version, Python requirement, dependency extras, scripts, and distribution metadata."
       }
     ],
@@ -3567,7 +3594,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled Custom Function Manager capture declaration, accessibility text, capture target, and generated visual projection."
       },
       {
@@ -3686,7 +3713,7 @@
   },
   {
     "path": "docs/source/user_guide/dtype_conversion.rst",
-    "source_sha256": "15887645e3b1f7ffc098364060108c42fcd72f2be9de9968ece8f3610ed74bd1",
+    "source_sha256": "c95144eee07fe4134768fd2e839cb25dfaa9d61e9794332c8481ccfc39a95d4c",
     "audience": [
       "pipeline authors"
     ],
@@ -3695,7 +3722,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -3708,6 +3735,21 @@
         "sha256": "99823105b0ae59054df1d84013633b8b6628d0a6dc3326383199ac7c65c69bed",
         "role": "Declares decorators that write independent input, output, and execution memory roles plus dtype policy."
       },
+      {
+        "path": "external/arraybridge/src/arraybridge/array_operations.py",
+        "sha256": "7e9ebda3d058702cdf8662dc5ab1faf1254649f3cbde76fa0adcbe02677fa103",
+        "role": "Defines NumPy float-to-integer scaling and integer-to-integer casting at the callable dtype boundary."
+      },
+      {
+        "path": "openhcs/processing/backends/processors/numpy_processor.py",
+        "sha256": "311634ec55ec8ddefe05118329d208e4b33df86f81d54ca4e258e7f4d2dbc980",
+        "role": "Declares the decorated projection function used in the 8-bit materialisation example."
+      },
+      {
+        "path": "external/PolyStore/src/polystore/disk.py",
+        "sha256": "cf089b8c79f86099a7cea1b6cbe43ceaec6331196a44b43183f2e64b7746c219",
+        "role": "Writes materialised TIFF pixels at the dtype supplied by the processing result."
+      },
       {
         "path": "tests/unit/test_callable_contract.py",
         "sha256": "493f76a54f5fe024ca8f10c53b1f810b8c369626ad7141205b42ef3a78282137",
@@ -3720,7 +3762,8 @@
       }
     ],
     "findings": [
-      "The task guide told users to change a desktop or step setting without naming the control or showing an executable override."
+      "The task guide told users to change a desktop or step setting without naming the control or showing an executable override.",
+      "The callable override lacked a concrete 8-bit materialisation example and warnings about NumPy scaling, integer wrapping, downstream values, and auxiliary outputs."
     ],
     "disposition": "revise",
     "validation": [
@@ -3731,7 +3774,8 @@
       "Passed ./.venv/bin/python -m sphinx -E -W --keep-going -b html docs/source <temporary-build-directory>: 153 source files rendered without warnings.",
       "On 2026-08-24, re-read the complete page against the changed declaration, dependency, UI state, knowledge, and test authorities named by this record; the documented behavior and ownership boundaries remain accurate.",
       "2026-09-08: targeted 0.8.3 authority-delta review, retaining the earlier full-page review. Checked affected catalogue ownership, code round-trip, runtime-setting and endpoint lifecycle claims against the changed declarations. Updated the code-editing, dtype, callable-authoring and connection explanations where behaviour changed. Dependency and version changes do not alter the retained installation or package-ownership descriptions. Focused source/ObjectState round-trip and callable-contract checks passed 53 tests; this is not a new whole-document audit.",
-      "2026-09-22 PR #126 targeted authority-delta review: re-read the complete page against `openhcs/core/config.py`; retained the supported claims, findings, and disposition, then refreshed only these compared evidence hashes. Review scope and the separate blocking runtime evidence are recorded in `docs/audits/pr126_authority_delta_review_20260922.md`."
+      "2026-09-22 PR #126 targeted authority-delta review: re-read the complete page against `openhcs/core/config.py`; retained the supported claims, findings, and disposition, then refreshed only these compared evidence hashes. Review scope and the separate blocking runtime evidence are recorded in `docs/audits/pr126_authority_delta_review_20260922.md`.",
+      "2026-09-24: re-read the full how-to and verified the new callable-level UINT8 materialisation example instantiates in the source checkout; direct NumPy-backed projection checks confirmed float scaling and integer wrapping. Reviewed ArrayBridge wrapper, NumPy scaling, the example callable, and the disk TIFF writer."
     ]
   },
   {
@@ -3755,7 +3799,7 @@
       },
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the default directory filenames and replicate-local normalization method."
       },
       {
@@ -3878,7 +3922,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the documentation-enabled execution-log capture, caption, accessibility text, dimensions, and source evidence."
       }
     ],
@@ -3950,7 +3994,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the local-MCP endpoint-startup scenario, representative poster, caption, description, alt text, dimensions, and release evidence."
       },
       {
@@ -4048,7 +4092,7 @@
     "authority": [
       {
         "path": "openhcs/core/config.py",
-        "sha256": "628b338097814f3d0297c28da8d016252214ff2253aee2e4946bad09f5890ea9",
+        "sha256": "ef81b50ee22b8da69513fd50d6e45a929117fa4bfaa62a20ef08a4c02531c043",
         "role": "Declares the supported OpenHCS configuration dataclasses, nested scopes, defaults, and field help metadata."
       },
       {
@@ -4098,7 +4142,7 @@
       },
       {
         "path": "scripts/gallery_catalog.py",
-        "sha256": "e6516488d7024771c35faf1a25d3ec3abc3b2f21830a8b318c9665d9469c5c0a",
+        "sha256": "bda42a36c1c510af7ac587dc2642548758d28c4a0061d581ebe38a5be4fb3743",
         "role": "Owns the Napari ROI-navigation and Fiji ROI-review scenarios, representative images, captions, descriptions, alt text, dimensions, and release evidence."
       }
     ],
diff --git a/docs/source/concepts/storage_system.rst b/docs/source/concepts/storage_system.rst
index 23a0effbda..66f05d5944 100644
--- a/docs/source/concepts/storage_system.rst
+++ b/docs/source/concepts/storage_system.rst
@@ -26,6 +26,23 @@ enum. OpenHCS contributes a fieldless registered subtype so those exact storage
 identities participate in global, pipeline, and step configuration without a
 second enum or field declaration.
 
+Disk TIFF compression
+---------------------
+
+``TiffConfig`` controls lossless compression for disk-backed TIFF outputs,
+including ordinary main-flow images and explicitly materialized named images.
+It is separate from Zarr compression and does not change non-TIFF artifacts or
+viewer streams. The default ``NONE`` retains uncompressed output; ``DEFLATE``
+uses the declared ``compression_level`` from 1 to 9. PolyStore owns the codec
+and writer behavior, while OpenHCS resolves the configuration for a pipeline
+and passes it to disk materialization. See :doc:`../reference/configuration`
+for exact fields and defaults.
+
+Compression preserves the dtype and pixel values produced by the callable.
+For a smaller 8-bit display image, set the existing callable-level dtype policy
+on the image-producing function instead; this changes values before storage.
+See :doc:`../user_guide/dtype_conversion` for the conversion boundaries.
+
 Artifacts first, paths second
 -----------------------------
 
diff --git a/docs/source/guide_for_biologists/configuration_reference.rst b/docs/source/guide_for_biologists/configuration_reference.rst
index 033b6a574e..801fbdeadf 100644
--- a/docs/source/guide_for_biologists/configuration_reference.rst
+++ b/docs/source/guide_for_biologists/configuration_reference.rst
@@ -120,6 +120,13 @@ Storage, paths, and persistence
   Read, intermediate, and persistent storage choices plus Zarr compression and
   chunking.
 
+``TiffConfig``
+  Optional lossless compression for disk-backed TIFF output, including saved
+  main-flow images and named image artifacts. The default is uncompressed;
+  enabling ``DEFLATE`` does not affect Zarr, other file formats, or viewer
+  streaming. The codec and level are resolved with the pipeline configuration
+  before execution.
+
 ``PathPlanningConfig``
   Output workspace/root placement, directory naming, and which processed wells
   seed the automatic main-flow output plate. ``well_filter=0`` keeps that
diff --git a/docs/source/user_guide/dtype_conversion.rst b/docs/source/user_guide/dtype_conversion.rst
index 0f020902d6..a410a1cb63 100644
--- a/docs/source/user_guide/dtype_conversion.rst
+++ b/docs/source/user_guide/dtype_conversion.rst
@@ -27,13 +27,59 @@ The equivalent step declaration is:
 
 .. code-block:: python
 
-   from arraybridge.decorators import DtypeConversion
    from openhcs.core.config import LazyDtypeConfig
+   from arraybridge.decorators import DtypeConversion
 
    step.dtype_config = LazyDtypeConfig(
        default_dtype_conversion=DtypeConversion.PRESERVE_INPUT,
    )
 
+Save an 8-bit visualisation
+---------------------------
+
+For a display image that does not need its original precision, set ``UINT8``
+on the image-producing callable in the function pattern and materialise that
+step's result:
+
+.. code-block:: python
+
+   from openhcs.core.config import LazyDtypeConfig, LazyStepMaterializationConfig
+   from openhcs.core.steps.function_step import FunctionStep
+   from openhcs.processing.backends.processors.numpy_processor import create_projection
+   from arraybridge.decorators import DtypeConversion
+
+   preview_step = FunctionStep(
+       func=(
+           create_projection,
+           {
+               "dtype_config": LazyDtypeConfig(
+                   default_dtype_conversion=DtypeConversion.UINT8,
+               ),
+           },
+       ),
+       name="8-bit projection for review",
+       step_materialization_config=LazyStepMaterializationConfig(enabled=True),
+   )
+
+Use this example with a floating-point image stack. The callable-level policy
+converts the main result before materialisation. When TIFF is the selected
+output format, the disk file therefore contains 8-bit pixels.
+The policy belongs to this callable occurrence, not to every function in the
+pipeline. Later steps using this result also receive its 8-bit values, so keep
+the conversion on a terminal review route if analysis still needs full
+precision.
+
+Check the values before choosing this policy. For NumPy-backed callables,
+float-to-``UINT8`` conversion scales the minimum and maximum of each
+non-constant callable result to the 8-bit range. Integer-to-``UINT8``
+conversion casts instead: values outside 0--255 can wrap. Neither is suitable
+for preserving quantitative intensities or object-label identities. A
+tuple-returning callable converts only its first, main result; it does not
+convert auxiliary named outputs.
+
+To save space without changing pixel values, use lossless disk TIFF compression
+instead. See :doc:`../concepts/storage_system` for the separate storage policy.
+
 Compile again after changing the policy. Do not cast merely to cross
 NumPy/CuPy/Torch boundaries; memory conversion and dtype policy are separate
 declarations.
diff --git a/external/PolyStore b/external/PolyStore
index 6534b10e7a..0efe67fdd1 160000
--- a/external/PolyStore
+++ b/external/PolyStore
@@ -1 +1 @@
-Subproject commit 6534b10e7a4dc077fe4d0a710bb05b995ee1ba57
+Subproject commit 0efe67fdd14985bf90cee6e0f0c4735d41d265d1
diff --git a/openhcs/core/config.py b/openhcs/core/config.py
index 8aec5091bc..8aaa01daba 100644
--- a/openhcs/core/config.py
+++ b/openhcs/core/config.py
@@ -69,6 +69,7 @@ class StreamingConfigMeta(EnableableMeta, AutoRegisterMeta):
 Lz4ZarrCompressorFactory = _polystore_config.Lz4ZarrCompressorFactory
 ZstdZarrCompressorFactory = _polystore_config.ZstdZarrCompressorFactory
 ZarrChunkStrategy = _polystore_config.ZarrChunkStrategy
+TiffCompression = _polystore_config.TiffCompression
 
 
 class MaterializationBackend(Enum):
@@ -616,6 +617,16 @@ class ZarrConfig(AnnotatedDataclassValidationMixin, _polystore_config.ZarrConfig
     """
 
 
+@abbreviation("tiff")
+@global_pipeline_config(
+    inherit_as_none=False,
+    field_abbreviations={"compression": "codec", "compression_level": "level"},
+)
+@dataclass(frozen=True)
+class TiffConfig(AnnotatedDataclassValidationMixin, _polystore_config.TiffConfig):
+    """Lossless TIFF output settings shared by image and artifact materialization."""
+
+
 @abbreviation("vfs")
 @global_pipeline_config(always_viewable_fields=["materialization_backend"])
 @dataclass(frozen=True)
diff --git a/openhcs/core/context/processing_context.py b/openhcs/core/context/processing_context.py
index ac44a2abab..e9a6f47172 100644
--- a/openhcs/core/context/processing_context.py
+++ b/openhcs/core/context/processing_context.py
@@ -19,6 +19,7 @@
     AnalysisConsolidationConfig,
     PlateMetadataConfig,
     StreamingConfig,
+    TiffConfig,
 )
 from openhcs.core.compiled_step_plan import CompiledStepPlan
 from openhcs.core.debug import (
@@ -97,6 +98,7 @@ def __init__(
         filemanager: FileManager | None = None,
         analysis_consolidation_config: AnalysisConsolidationConfig | None = None,
         plate_metadata_config: PlateMetadataConfig | None = None,
+        tiff_config: TiffConfig | None = None,
         auto_add_output_plate_to_plate_manager: bool = False,
         output_plate_root: str | None = None,
         transport_config: ZMQConfig = OPENHCS_ZMQ_CONFIG,
@@ -147,6 +149,7 @@ def __init__(
             if plate_metadata_config is not None
             else PlateMetadataConfig()
         )
+        self.tiff_config = tiff_config if tiff_config is not None else TiffConfig()
         self.auto_add_output_plate_to_plate_manager = (
             auto_add_output_plate_to_plate_manager
         )
diff --git a/openhcs/core/orchestrator/orchestrator.py b/openhcs/core/orchestrator/orchestrator.py
index 22ed3ea28a..09d3836fb2 100644
--- a/openhcs/core/orchestrator/orchestrator.py
+++ b/openhcs/core/orchestrator/orchestrator.py
@@ -574,6 +574,7 @@ def create_context(self, axis_id: str) -> ProcessingContext:
                 effective_config.analysis_consolidation_config
             ),
             plate_metadata_config=effective_config.plate_metadata_config,
+            tiff_config=effective_config.tiff_config,
             auto_add_output_plate_to_plate_manager=(
                 effective_config.auto_add_output_plate_to_plate_manager
             ),
diff --git a/openhcs/core/steps/function_artifact_materialization.py b/openhcs/core/steps/function_artifact_materialization.py
index d27788c823..6bfc6e5b63 100644
--- a/openhcs/core/steps/function_artifact_materialization.py
+++ b/openhcs/core/steps/function_artifact_materialization.py
@@ -405,7 +405,12 @@ def backend_kwargs(
                     f"context values: {sorted(conflicts)!r}."
                 )
             values.update(contextual_values)
-            result[backend] = RawBackendKwargs(values)
+            result[backend] = RawBackendKwargs(
+                values,
+                tiff_config=(
+                    kwargs.tiff_config if isinstance(kwargs, RawBackendKwargs) else None
+                ),
+            )
 
         streamable_viewer_surfaces = self.streamable_viewer_surfaces(
             filemanager=filemanager,
@@ -496,7 +501,7 @@ def backend_plan(
             )
         )
         return ArtifactMaterializationBackendPlan(
-            persistent_backend_kwargs=self.persistent_backend_kwargs(),
+            persistent_backend_kwargs=self.persistent_backend_kwargs(context),
             streaming_viewer_surfaces=(
                 {
                     config.backend.value: config.streaming_viewer_surface(context)
@@ -514,7 +519,7 @@ def backend_plan(
         )
 
     @abstractmethod
-    def persistent_backend_kwargs(self) -> BackendKwargs:
+    def persistent_backend_kwargs(self, context: "ProcessingContext") -> BackendKwargs:
         """Return persistent materialization backends owned by this policy."""
 
 
@@ -525,8 +530,14 @@ class PersistentArtifactMaterializationTargetPlan(ArtifactMaterializationTargetP
     target_key = "persistent"
     backend: str
 
-    def persistent_backend_kwargs(self) -> BackendKwargs:
-        return {self.backend: RawBackendKwargs()}
+    def persistent_backend_kwargs(self, context: "ProcessingContext") -> BackendKwargs:
+        return {
+            self.backend: RawBackendKwargs(
+                tiff_config=(
+                    context.tiff_config if self.backend == Backend.DISK.value else None
+                ),
+            )
+        }
 
 
 class StreamingOnlyArtifactMaterializationTargetPlan(ArtifactMaterializationTargetPlan):
@@ -534,7 +545,7 @@ class StreamingOnlyArtifactMaterializationTargetPlan(ArtifactMaterializationTarg
 
     target_key = "streaming_only"
 
-    def persistent_backend_kwargs(self) -> BackendKwargs:
+    def persistent_backend_kwargs(self, context: "ProcessingContext") -> BackendKwargs:
         return {}
 
 
diff --git a/openhcs/core/steps/function_io.py b/openhcs/core/steps/function_io.py
index 64236b7bf6..d2e5e5e38b 100644
--- a/openhcs/core/steps/function_io.py
+++ b/openhcs/core/steps/function_io.py
@@ -10,6 +10,7 @@
 from typing import TYPE_CHECKING, Callable, ClassVar, Mapping, Sequence, TypeAlias
 
 from metaclass_registry import AutoRegisterMeta
+from polystore.config import tiff_write_batches
 from polystore.zarr_batch import ZarrBatchAxis, ZarrBatchAxisRole, ZarrBatchLayout
 
 from openhcs.constants.constants import (
@@ -380,9 +381,17 @@ def save_materialized_data(
         materialized_paths,
         materialized_backend,
     )
-    filemanager.save_batch(
-        payloads, list(materialized_paths), materialized_backend, **save_kwargs
+    tiff_config = (
+        context.tiff_config if materialized_backend == Backend.DISK.value else None
     )
+    for indices, batch_config in tiff_write_batches(materialized_paths, tiff_config):
+        filemanager.save_batch(
+            [payloads[index] for index in indices],
+            [materialized_paths[index] for index in indices],
+            materialized_backend,
+            **save_kwargs,
+            **({"tiff_config": batch_config} if batch_config is not None else {}),
+        )
 
 
 def get_all_image_paths(
diff --git a/openhcs/processing/materialization/core.py b/openhcs/processing/materialization/core.py
index c8733dc8d5..437f42ab19 100644
--- a/openhcs/processing/materialization/core.py
+++ b/openhcs/processing/materialization/core.py
@@ -22,6 +22,7 @@
 import numpy as np
 import pandas as pd
 from metaclass_registry import AutoRegisterMeta
+from polystore.config import TiffConfig, tiff_write_batches
 from polystore.streaming.viewer_transport import (
     PathMappedViewerStreamSourceMetadata,
     ViewerStreamBackendKwargs,
@@ -158,6 +159,7 @@ class RawBackendKwargs(BackendCallKwargs, Mapping[str, MaterializationValue]):
 
     backend_kwargs_kind = "raw"
     values: Mapping[str, MaterializationValue] = field(default_factory=dict)
+    tiff_config: TiffConfig | None = None
 
     def __getitem__(self, key: str) -> MaterializationValue:
         return self.values[key]
@@ -172,13 +174,29 @@ def to_filemanager_kwargs(
         self,
         output: Output,
     ) -> dict:
-        return dict(self.values)
+        values = dict(self.values)
+        if self.tiff_config is not None and self.tiff_config.applies_to_path(
+            output.path
+        ):
+            values["tiff_config"] = self.tiff_config
+        return values
 
     def filemanager_batches(
         self,
         outputs: Sequence[Output],
     ) -> tuple[tuple[tuple[Output, ...], dict], ...]:
-        return ((tuple(outputs), dict(self.values)),)
+        return tuple(
+            (
+                tuple(outputs[index] for index in indices),
+                {
+                    **self.values,
+                    **({"tiff_config": config} if config is not None else {}),
+                },
+            )
+            for indices, config in tiff_write_batches(
+                tuple(output.path for output in outputs), self.tiff_config
+            )
+        )
 
 
 class TabularRow(dict[str, MaterializationValue]):
diff --git a/pyproject.toml b/pyproject.toml
index b20d05c0c7..cede0e82e5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -102,7 +102,7 @@ dependencies = [
     "python-introspect>=0.1.14,<0.2",
     "metaclass-registry>=0.2.1,<0.3",
     "arraybridge>=0.3.4,<0.4",
-    "polystore>=0.2.18,<0.3",
+    "polystore>=0.2.19,<0.3",
     "pyqt-reactive>=0.3.24,<0.4",
 ]
 
diff --git a/scripts/gallery_catalog.py b/scripts/gallery_catalog.py
index c445344ca6..701d45636b 100644
--- a/scripts/gallery_catalog.py
+++ b/scripts/gallery_catalog.py
@@ -25,7 +25,6 @@
 from pyqt_reactive.services.system_monitor_actions import SystemMonitorAction
 from python_introspect import dataclass_from_mapping
 
-from openhcs.agent.dto.execution import ExecutionConnectionSpec
 from openhcs.agent.ui_bridge_actions import PlateManagerAction
 from openhcs.agent.ui_bridge_identities import (
     GlobalConfigWindowIdentity,
@@ -41,6 +40,7 @@
 from openhcs.serialization.json import JsonValue, to_jsonable
 
 if TYPE_CHECKING:
+    from openhcs.agent.dto.execution import ExecutionConnectionSpec
     from openhcs.pyqt_gui.services.step_scope_identity import StepEditorScope
 
 RELEASE_MEDIA_SCHEMA_VERSION = "openhcs.release-media.v7"
diff --git a/tests/unit/test_config_document.py b/tests/unit/test_config_document.py
index 57621a2d92..157caefc62 100644
--- a/tests/unit/test_config_document.py
+++ b/tests/unit/test_config_document.py
@@ -7,7 +7,12 @@
 
 import pytest
 
-from openhcs.core.config import GlobalPipelineConfig, PipelineConfig
+from openhcs.core.config import (
+    GlobalPipelineConfig,
+    PipelineConfig,
+    TiffCompression,
+    TiffConfig,
+)
 from openhcs.core.config_document import (
     ConfigDocumentAuthority,
     ConfigDocumentField,
@@ -27,6 +32,12 @@ def test_config_document_field_owns_exact_public_name() -> None:
     "config",
     (
         GlobalPipelineConfig(num_workers=3),
+        GlobalPipelineConfig(
+            tiff_config=TiffConfig(
+                compression=TiffCompression.DEFLATE,
+                compression_level=3,
+            )
+        ),
         PipelineConfig(),
     ),
 )
diff --git a/tests/unit/test_function_artifact_materialization.py b/tests/unit/test_function_artifact_materialization.py
index dfdb539877..fce6077a7e 100644
--- a/tests/unit/test_function_artifact_materialization.py
+++ b/tests/unit/test_function_artifact_materialization.py
@@ -43,7 +43,7 @@
     RuntimeExecutionAxisScope,
 )
 from openhcs.core.components.parser_metaprogramming import FilenameParseResult
-from openhcs.core.config import AnalysisConsolidationConfig, WellFilterMode
+from openhcs.core.config import AnalysisConsolidationConfig, TiffConfig, WellFilterMode
 from openhcs.core.function_patterns import (
     DEFAULT_GROUP_KEY,
     CompiledFunctionGroup,
@@ -468,6 +468,7 @@ def _context(filemanager):
     context.axis_id = "A01"
     context.step_axis_filters = {}
     context.analysis_consolidation_config = AnalysisConsolidationConfig()
+    context.tiff_config = TiffConfig()
     return context
 
 
diff --git a/tests/unit/test_function_artifact_materialization_io_hotpath.py b/tests/unit/test_function_artifact_materialization_io_hotpath.py
index d8fe1aa816..b6627f4cfa 100644
--- a/tests/unit/test_function_artifact_materialization_io_hotpath.py
+++ b/tests/unit/test_function_artifact_materialization_io_hotpath.py
@@ -7,6 +7,7 @@
 import numpy as np
 import pytest
 from polystore.base import DataSink
+from polystore.config import TiffCompression, TiffConfig
 from polystore.streaming.identity import StreamProducerIdentity
 
 from openhcs.core.steps.function_artifact_materialization import (
@@ -15,6 +16,7 @@
 )
 from openhcs.processing.materialization.core import (
     MaterializationSpec,
+    Output,
     RawBackendKwargs,
 )
 from openhcs.processing.materialization.options import ImageFileOptions
@@ -38,6 +40,26 @@ def save_batch(self, data_list, identifiers, **kwargs):
         raise AssertionError("This projection test must not save")
 
 
+def test_persistent_tiff_kwargs_apply_only_to_tiff_outputs() -> None:
+    config = TiffConfig(compression=TiffCompression.DEFLATE)
+    kwargs = RawBackendKwargs(tiff_config=config)
+    outputs = (
+        Output(path="/results/summary.csv", content="well,count\nA01,1\n"),
+        Output(path="/results/labels.tif", content=np.zeros((8, 8), dtype=np.int32)),
+        Output(path="/results/labels2.tiff", content=np.zeros((8, 8), dtype=np.int32)),
+    )
+
+    batches = kwargs.filemanager_batches(outputs)
+
+    assert tuple(output.path for output in batches[0][0]) == ("/results/summary.csv",)
+    assert batches[0][1] == {}
+    assert tuple(output.path for output in batches[1][0]) == (
+        "/results/labels.tif",
+        "/results/labels2.tiff",
+    )
+    assert batches[1][1] == {"tiff_config": config}
+
+
 class _FileManager:
     def __init__(self) -> None:
         self.backend = _PersistentBackend()
diff --git a/tests/unit/test_tiff_output_compression.py b/tests/unit/test_tiff_output_compression.py
new file mode 100644
index 0000000000..7ada403ad4
--- /dev/null
+++ b/tests/unit/test_tiff_output_compression.py
@@ -0,0 +1,72 @@
+"""Lossless TIFF compression crosses the declared OpenHCS output boundary."""
+
+from types import SimpleNamespace
+
+import numpy as np
+import tifffile
+from polystore.disk import DiskBackend
+from polystore.filemanager import FileManager
+
+from openhcs.constants.constants import Backend
+from openhcs.core.config import GlobalPipelineConfig, TiffCompression, TiffConfig
+from openhcs.core.steps.function_artifact_materialization import (
+    PersistentArtifactMaterializationTargetPlan,
+)
+from openhcs.core.steps.function_io import save_materialized_data
+from openhcs.processing.materialization import (
+    ImageFileOptions,
+    MaterializationSpec,
+    MaterializedFilenameIdentity,
+    materialize,
+)
+
+
+def test_configured_main_flow_tiff_output_is_lossless(tmp_path) -> None:
+    config = TiffConfig(compression=TiffCompression.DEFLATE, compression_level=3)
+    assert GlobalPipelineConfig().tiff_config == TiffConfig()
+    pixels = np.zeros((2, 256, 256), dtype=np.int32)
+    pixels[0, 40:60, 80:100] = 5
+    path = tmp_path / "labels.tif"
+    context = SimpleNamespace(
+        microscope_handler=SimpleNamespace(parser=object(), microscope_type="test"),
+        tiff_config=config,
+    )
+
+    save_materialized_data(
+        FileManager({Backend.DISK.value: DiskBackend()}),
+        [pixels],
+        [str(path)],
+        Backend.DISK.value,
+        None,
+        context,
+        "A01",
+    )
+
+    with tifffile.TiffFile(path) as output:
+        assert output.pages[0].compression.value != 1
+    np.testing.assert_array_equal(tifffile.imread(path), pixels)
+
+
+def test_configured_named_artifact_tiff_output_is_lossless(tmp_path) -> None:
+    config = TiffConfig(compression=TiffCompression.DEFLATE, compression_level=3)
+    pixels = np.zeros((2, 256, 256), dtype=np.int32)
+    pixels[1, 60:80, 90:110] = 11
+    path = materialize(
+        MaterializationSpec(
+            ImageFileOptions(
+                filename_suffix=".tif",
+                filename_identity=MaterializedFilenameIdentity.ARTIFACT_NAME,
+            )
+        ),
+        pixels,
+        str(tmp_path / "artifact"),
+        FileManager({Backend.DISK.value: DiskBackend()}),
+        backends=[Backend.DISK.value],
+        backend_kwargs=PersistentArtifactMaterializationTargetPlan(
+            backend=Backend.DISK.value
+        ).persistent_backend_kwargs(SimpleNamespace(tiff_config=config)),
+    )
+
+    with tifffile.TiffFile(path) as output:
+        assert output.pages[0].compression.value != 1
+    np.testing.assert_array_equal(tifffile.imread(path), pixels)