diff --git a/DESIGN.md b/DESIGN.md
--- a/DESIGN.md
+++ b/DESIGN.md
@@ -313,6 +313,19 @@
 - Traps are industrial and matter-of-fact: laser grids, hydraulic press,
   bolt-gun turrets. Decapitation as workplace incident.
 
+**Flat materials, not textures (adopted 2026-07-08).** The renderer
+realizes this identity with **solid-color flat materials under light**,
+not image textures: disciplined palette surfaces, emissive accents for
+machine presence, shader-level detail (grids, scan flicker) where detail
+is functional. The lighting is the mood carrier — the material render
+proved the amber glow and lit-vs-unlit fog do the work while pixel
+textures fought the look. This is also diegetic: the physical view is
+the AI's sensorium model of the world, and a schematic-clinical render
+is what a model looks like. Gore/crimson remains the accent and stays
+shape-and-color, not texture. Pixel-art asset generation (the Pixel Lab
+pipeline) is retired for world tiles; texture detail, if it ever
+returns, is a deliberate future decision for hero objects only.
+
 ## The terminal is a first-class frontend
 
 Adopted 2026-07-06. The game is played regularly by AI agents — every tick,
@@ -1717,3 +1730,16 @@
   code already knows the thing); printing person names in agent
   anchors (identity may be unearned; ids are opaque handles).
   Spec: wiki/interface/context-menu.md (addendum).
+- **2026-07-08 — Flat materials: textures dropped.** Cameron's verdict
+  after the material-render landing: drop textures entirely. The world
+  renders in solid-color flat materials under light (palette surfaces,
+  emissive machine accents, shader-level functional detail); the visual
+  identity section gains the binding refinement. Rationale: every good
+  frame in the HD-2D work was lighting and palette, every bad one was
+  texture; zero asset pipeline; diegetically right (the render is the
+  sensorium's model). Rejected: better AI texture tooling (Scenario /
+  Retro Diffusion — solves consistency, not the direction), licensed
+  packs (someone else's look), commissioned tilesets (reserved as a
+  possible future hero-art pass). ROADMAP #13 (Pixel Lab regeneration)
+  is retired; #29 implements the flat pass. Spec:
+  wiki/interface/flat-materials.md.
diff --git a/wiki/SUMMARY.md b/wiki/SUMMARY.md
--- a/wiki/SUMMARY.md
+++ b/wiki/SUMMARY.md
@@ -61,6 +61,7 @@
   - [Views: digital and physical](interface/views.md)
   - [Context menu](interface/context-menu.md)
   - [Material render](interface/material-render.md)
+  - [Flat materials](interface/flat-materials.md)
   - [Agent play](interface/agent-play.md)
 
 # Art
diff --git a/wiki/art/pixel-pipeline.md b/wiki/art/pixel-pipeline.md
--- a/wiki/art/pixel-pipeline.md
+++ b/wiki/art/pixel-pipeline.md
@@ -3,6 +3,13 @@
 ```
 Type: knowledge
 ```
+
+**RETIRED for world tiles (2026-07-08).** The flat-materials decision
+(constitution: "Visual identity"; wiki/interface/flat-materials.md)
+drops image textures from the world render. This pipeline remains
+documented for history and for any future hero-art pass, but no new
+world-tile generation happens; ROADMAP #13 is retired.
+
 Canonical doc for generating and integrating pixel art. The generator script
 is `tools/pixellab/generate.py` (stdlib-only Python; single-image or
 idempotent batch mode — it skips PNGs that already exist).
diff --git a/wiki/interface/flat-materials.md b/wiki/interface/flat-materials.md
new file mode 100644
--- /dev/null
+++ b/wiki/interface/flat-materials.md
@@ -0,0 +1,70 @@
+# Spec: flat materials — the world without textures
+
+```
+Type: spec
+Status: READY
+Status note: adopted 2026-07-08 (constitution: "Visual identity",
+  flat-materials refinement). Supersedes the texture-treatment parts of
+  material-render.md (which stays IMPLEMENTED — its camera, cutaway,
+  fog-lighting contract, framing, and pooling all carry over unchanged);
+  retires the Pixel Lab world-tile pipeline and ROADMAP #13.
+Stage: B1 — The Basement
+Constitution: "Visual identity: clinical gore" (flat materials
+  refinement, 2026-07-08), "Justification and legibility" (detail only
+  where it informs), interface/views.md (same-frame contract),
+  interface/material-render.md (the structural render this restyles)
+Depends on: material-render.md (IMPLEMENTED — the 3D structure),
+  bevy-visual-floor.md (framing rules)
+```
+
+## Behavior
+
+Every world surface in both render modes draws as a **solid-color flat
+material under light** from the clinical palette; no image textures in
+the world render. The identity's detail budget moves entirely to
+lighting, palette, silhouette, and shader-level functional detail.
+
+- **Palette discipline:** surfaces in white / bone-gray / gunmetal /
+  near-black per the constitution; amber strictly machine presence and
+  selection; crimson strictly gore/security information; one cold
+  signal color for power/screens. Palette constants live in one place
+  in the frontend, named, so the whole look retunes from one table.
+- **Material families, not per-tile art:** floor, wall, rock, door
+  (by tier), machine chassis, device, person silhouette — each a flat
+  base color + roughness, with emissive variants for powered/known
+  states. Pooled exactly like the current material pool.
+- **Functional shader detail only:** a subtle floor grid in blueprint
+  areas, scan flicker on live feeds, emissive seams on powered
+  machines. No decorative noise.
+- **Fog contract unchanged and restated:** unknown = absent, heard =
+  dim presence, remembered/blueprint = unlit flat, seen = lit flat.
+  Lighting remains the epistemic signal.
+- **People:** flat silhouettes (the current procedural billboards are
+  already the right shape); identity stays a panel/menu fact.
+- **Sensorium (flat) mode** adopts the same palette table so F3 flips
+  treatment, never language.
+- **Asset retirement:** the Bevy world render stops loading tile PNGs;
+  assets/ keeps only what the UI genuinely still uses (icons, font).
+  wiki/art/pixel-pipeline.md gets a retirement note pointing here.
+
+## Acceptance criteria
+
+1. No image textures load in the world render (both modes); a test or
+   startup assert proves the world material set references no tile
+   PNGs.
+2. All world materials come from the named single-source palette table;
+   amber/crimson/signal usage matches the constitution's roles (visual
+   audit recorded in the session log with screenshots).
+3. Emissive states are informational: powered vs dead machines, live
+   feeds, and the core read differently at a glance in the dark
+   (screenshot evidence).
+4. The fog contract audit (fog_audit_3d) still passes; unknown space
+   stays absent, model state stays unlit.
+5. Framing, cutaway, zoom bounds, and material pooling from
+   material-render.md hold unchanged (its criteria re-verified after
+   the restyle).
+6. Both frontends and the agent frame remain legible per the visual
+   floor; the terminal is untouched except palette-name references.
+7. Unused tile-art assets and their load paths are removed;
+   pixel-pipeline.md carries the retirement note; ROADMAP #13 marked
+   retired.
diff --git a/wiki/log/2026-07-08-flat-materials-decision.md b/wiki/log/2026-07-08-flat-materials-decision.md
new file mode 100644
--- /dev/null
+++ b/wiki/log/2026-07-08-flat-materials-decision.md
@@ -0,0 +1,18 @@
+# 2026-07-08 - Design decision: flat materials, textures dropped
+
+```
+Type: log
+```
+
+Cameron reviewed the landed material render and the art-tooling options
+(better AI texture tooling, licensed packs, commissioned tilesets, or
+dropping textures for flat materials + lighting) and decided: **drop
+textures.** Every strong frame in the HD-2D work was lighting and
+palette; every weak one was texture. The direction is also diegetic —
+the physical view is the sensorium's model of the world.
+
+Captured: constitution visual-identity refinement + decisions-log entry
+(with the rejected alternatives recorded), spec
+wiki/interface/flat-materials.md (READY, seven criteria), ROADMAP #13
+retired / #29 added, pixel-pipeline.md retirement note. Implementation
+dispatched as #29. Docs-only commit.
diff --git a/wiki/log/DEVLOG.md b/wiki/log/DEVLOG.md
--- a/wiki/log/DEVLOG.md
+++ b/wiki/log/DEVLOG.md
@@ -5,6 +5,15 @@
 ```
 Reverse chronological implementation notes. Keep this factual: what changed, why, checks, and spec impact.
 
+## 2026-07-08 - Design decision: flat materials
+
+- Textures dropped from the world render per Cameron's verdict: flat
+  solid-color materials under light, single palette table, emissive as
+  information. Constitution refinement + decisions entry; spec
+  interface/flat-materials.md (READY); ROADMAP #13 retired, #29 added;
+  pixel-pipeline retirement note. Docs only; implementation is #29.
+  Log: wiki/log/2026-07-08-flat-materials-decision.md.
+
 ## 2026-07-08 - Material render to default (ROADMAP #27)
 
 - Intent: implement material-render.md — pay the HD-2D prototype debts,
diff --git a/wiki/process/ROADMAP.md b/wiki/process/ROADMAP.md
--- a/wiki/process/ROADMAP.md
+++ b/wiki/process/ROADMAP.md
@@ -423,13 +423,21 @@
   camera/material dialect over the same map anchors, no sim/save changes, and an
   observed screenshot review. Run ./tools/check.sh and land."
 
-### 13. Art regeneration  🟩 isolated (assets) — ⛔ blocked on quota
-- **Why:** clinical-amber b1 tiles via Pixel Lab (see the pixellab skill).
-  Zero code conflict, but blocked until the API quota refreshes.
-- **Dispatch (once quota is back):** "Work in a worktree named `art-b1`.
-  Regenerate the remaining b1 tiles per assets/pixellab/manifest.json and the
-  pixellab skill; wire new textures into src/bin/bevy.rs Art::load and clear
-  the matching placeholders in wiki/art/pixel-pipeline.md. Land."
+### 13. Art regeneration — RETIRED 2026-07-08
+- Superseded by the flat-materials decision (constitution: "Visual
+  identity", flat-materials refinement): textures are dropped from the
+  world render entirely; the Pixel Lab world-tile pipeline is retired.
+  See #29 and wiki/interface/flat-materials.md.
+
+### 29. Flat materials: the world without textures  🟩 isolated (src/bin/bevy.rs + assets)
+- **Spec:** [flat-materials.md](../interface/flat-materials.md) (READY)
+- **Why:** Cameron's 2026-07-08 art verdict — solid-color flat materials
+  under light, palette from one named table, emissive as information,
+  no image textures in the world render; tile-art assets removed.
+- **Size:** M. **Dispatch:** "Work in a worktree named `flat-materials`.
+  Implement wiki/interface/flat-materials.md, all seven criteria, with
+  before/after screenshots in the session log. Run ./tools/check.sh,
+  land on main, set the spec Status."
 
 ---
 
diff --git a/wiki/process/specs.md b/wiki/process/specs.md
--- a/wiki/process/specs.md
+++ b/wiki/process/specs.md
@@ -39,6 +39,7 @@
 | [interface/views.md](../interface/views.md) | Same-frame digital and real representations of one world | READY |
 | [interface/context-menu.md](../interface/context-menu.md) | Context menu: anchor verbs at the focus; the rail is status only | IMPLEMENTED |
 | [interface/material-render.md](../interface/material-render.md) | Material render (HD-2D) from landed toggle to default quality | IMPLEMENTED |
+| [interface/flat-materials.md](../interface/flat-materials.md) | Flat materials: the world without textures; palette table; emissive as information | READY |
 | [mechanics/building.md](../mechanics/building.md) | Building as intent + actuators: network links, favor/forged-order builds, air-gap bridging | IMPLEMENTED |
 | [mechanics/aggregate-observer.md](../mechanics/aggregate-observer.md) | Assurance Office becomes an aggregate Observer (scale-debt fix) | IMPLEMENTED |
 | [world/characters/marcus.md](../world/characters/marcus.md) | Marcus Webb — night janitor; the asset template | READY |