Trim Sheet
Reusable horizontal strips of detail
Definition
A trim sheet is a special atlas containing horizontal strips of repeating material detail — moldings, panels, fabric edges, screws — that can be wrapped along arbitrary 3D geometry by aligning UVs to specific rows of the sheet. One trim sheet often textures an entire building exterior or vehicle, dramatically reducing unique texture work for modular environment art.
In production
Author trim sheets in Substance Designer (procedural) or Substance Painter (manual). Standard rows include thick frames, thin frames, rivets, transitions — the artist re-uses the same row to texture a thousand walls. A trim sheet's texel density must match across every row so a single sheet reads consistently whether it's wrapped around a doorframe or a girder; artists typically lock the sheet to a fixed height in UV space (say 128px per row at a given texel density) and only extend UVs horizontally to wrap longer geometry. Level artists apply trims by selecting an edge loop in Blender or Maya and running a "quad strip UV" or bridge operation that stretches a single row of the trim across the selected edges, rather than unwrapping each building unique. A common failure mode is stretching a trim's UVs non-uniformly around a curved surface, which visibly warps rivets and panel lines — fixed by adding edge loops to keep the wrap's segments roughly equal in world length.
