Beginner Core Concept

What is a Trim Sheet and How Do Game Artists Use Them?

Trim sheets are one of the most powerful and underused techniques in environment art. A single texture atlas containing a strip of tiling surfaces — reused across dozens of meshes — is how AAA studios produce high-quality environments without creating a unique texture for every single prop.

⏱ ~8 min read · 6 sections · Beginner friendly

Section 01

What is a Trim Sheet?

A trim sheet is a texture atlas — a single texture image — divided into horizontal strips, each containing a different tiling surface material. Artists UV-map different faces of their 3D meshes to different strips on the same sheet, so dozens of meshes can share one texture.

Think of it like a physical paint store sample card: a long strip with sections of concrete, metal edge, tile, and wood trim — all in one place. You pick a section for each surface of your prop rather than painting a completely new texture every time.

The key property: Each strip on a trim sheet tiles in one axis — usually horizontally. This means a UV island can repeat along the strip infinitely, which is what makes trim sheets ideal for walls, pillars, floor edges, architectural moulding, and any other surface that repeats in one direction.

Trim sheets are different from a standard texture atlas, where each object gets its own unique UV island on the shared texture. With a trim sheet, UV islands deliberately overlap strips — the same strip can be reused by multiple meshes and multiple faces of the same mesh. That's the whole point.

Section 02

Why Studios Use Them

In a large game environment you might have hundreds of unique props and surfaces. If each one had its own full texture set, you'd spend enormous time creating textures and saturate the GPU's texture memory at runtime. Trim sheets solve both problems.

Without trim sheets

50 props each need their own albedo, normal, roughness, metallic. That's 200+ texture files to create, manage, import, and load into VRAM. Production is slow and memory cost is high.

With trim sheets

One trim sheet covers 30–50 props. Memory cost is one texture set — four maps total. Production is faster because you paint once and reuse everywhere.

Games like Doom Eternal, The Last of Us, and Halo Infinite use trim sheets heavily for environment art. A small team can produce visually dense, detailed environments because the same trim sheet surfaces appear everywhere — on pillars, walls, corridors, and props — without any additional texture work per asset.

Fewer draw calls

Meshes sharing the same trim sheet material can be batched together — one draw call for many props instead of one per prop.

Lower VRAM

One 2048×2048 trim sheet covering 40 props uses far less GPU memory than 40 individual 512×512 texture sets.

Faster production

Paint the trim sheet once. Every asset that references it is automatically updated when you refine the sheet — no re-texturing individual props.

Section 03

Anatomy of a Trim Sheet

A typical trim sheet is a square texture — 2048×2048 or 4096×4096 — divided into horizontal strips of varying heights. Each strip is a complete, tiling PBR surface. The full sheet is a set of four maps: albedo, normal, roughness, and metallic.

Strip heights are typically 128–512 pixels depending on how much detail each surface needs. A highly detailed edge trim might get 256px of height. A simple flat panel fill might only need 128px. The remaining space in the 2048px canvas is filled with more strips.

Every strip must tile seamlessly. The left and right edges of each strip need to match — if the strip is sliced and repeated horizontally, the repeat should be invisible. Paint or bake with tiling in mind from the start.
Section 04

How the UV Layout Works

Using a trim sheet requires thinking about UVs differently from a standard unique-texture asset. Rather than maximising how much of the 0–1 UV space each island occupies, you're aligning specific faces to specific strips on the sheet.

01

Each face maps to a strip

You decide which strip each face of your mesh should show. The top of a wall might use the flat panel strip. The base might use the edge trim strip. You UV each face to land on the correct strip.

02

Islands can tile beyond 0–1

Unlike standard UV layouts, trim sheet UVs intentionally tile. A long wall face might have its UV island extend three or four repeats horizontally — the texture tiles across the surface automatically.

03

Islands from different meshes share strips

The pillar next to the wall uses the same edge trim strip as the wall's base. Their UV islands point to the same part of the texture — and that's exactly the intended behaviour.

04

Scale determines texel density

How tall you make the UV island vertically determines how much of the strip height is used — which controls the visual scale of the surface detail on the mesh. Match texel density to keep all surfaces consistent.

Overlapping UVs are intentional here. Normally, overlapping UV islands in channel 0 is an error. With trim sheets it's by design — many faces from many meshes all point to the same strip. The one exception: if you need Unreal's lightmap baking, the lightmap UV (channel 1) must still be non-overlapping.
Section 05

The Trim Sheet Workflow

Building and using a trim sheet follows a specific order. Getting this order right saves a lot of rework.

01

Plan your strips

Decide what surface types your game environment needs before touching a texture. List them out — edge bevel, painted metal panel, riveted detail, concrete base, rubber trim. These become your strips.

02

Create the sheet

Paint or bake each strip at consistent world-scale. A 256px strip at 2048 resolution should represent the same real-world height on every mesh that uses it — typically 10–30cm for a detail trim, larger for a panel fill.

03

Build or block out your meshes

Model your environment props and modular pieces with the trim sheet strips in mind. Keep surfaces flat where they'll use flat strips. Use geometry only where the silhouette changes.

04

UV to the sheet

Unwrap each face and position its UV island to sit on the correct strip. Scale UVs so the world-scale texel density matches your other assets. Let the island tile horizontally across long surfaces.

05

Assign one shared material

All props referencing the trim sheet share one material. Apply it to all meshes. Any refinements to the trim sheet texture update all props simultaneously.

When not to use a trim sheet

Trim sheets aren't the right tool for every asset. Hero props — the player's weapon, key story objects, character clothing — need unique textures to show fine individual detail and art direction that a shared strip can't provide. Use trim sheets for architectural surfaces, modular environment kits, and filler props. Use unique textures for anything the player examines up close.

Good trim sheet candidates

Walls, floors, pillars, corridors, structural panels, modular environment kits, background props, crates, containers, machinery casing.

Use unique textures instead

Player weapons, character costumes, key story props, hero objects, anything with fine individual markings, logos, or art-directed surface detail.

Section 06

Creating Trim Sheets in Trumble

Trumble's 2D texture painter is well-suited to building trim sheet strips. Open a new document at 2048×2048, use the grid overlay to divide the canvas into horizontal rows, and paint each strip as an independent PBR surface — albedo, roughness, metallic, and normal all in the same session.

For strips that need baked normal detail — a beveled edge, a row of rivets, a grating pattern — model a simple high-poly source in Blender and bake it into Trumble. The baked normal map for that strip captures all the surface depth without any mesh complexity in the final asset.

Paint strips

Use Trumble's layer system to paint each strip independently. Roughness and metallic channels let you define surface character per strip.

Bake strip normals

For geometric strip detail — bevels, bolts, vents — bake a high-poly source into the strip's UV region for accurate normal map depth.

Export as PBR set

Export the full trim sheet as an engine-ready texture pack — albedo, normal, and ORM — in the correct format for Unreal, Unity, or Godot.

Start small: Build a trim sheet with just three or four strips for your first attempt. One edge trim, one flat panel, one detail strip. UV a simple modular wall piece to use all three strips. That single exercise teaches you more about the workflow than reading about it — and you'll have a reusable sheet at the end of it.