Polypaint
Per-vertex colour in ZBrush
Definition
Polypaint is ZBrush's technique of painting colour directly onto a sculpt's vertices rather than onto a UV-mapped texture. Each vertex stores an RGB value — so the polycount sets the effective texture resolution. Polypaint is fast for blocking colour passes during sculpting and for generating an albedo basis that's baked to a UV-mapped texture at the retopology stage.
In production
High-density sculpts (10M+ polys) carry enough vertices that polypaint produces effectively photo-resolution colour information, which is why ZBrush artists often subdivide a mesh several extra levels purely to get finer polypaint detail before ever touching a UV-mapped texture. Bake polypaint to an albedo map during normal-map baking in Marmoset Toolbag or Substance Painter, feeding the high-poly sculpt with its vertex colours as the bake source against the low-poly's UVs. Because polypaint resolution is tied directly to polycount rather than an independent texture resolution setting, a sparse retopologized region of a sculpt will produce visibly blurry colour compared to a densely subdivided region — a common gotcha when artists DynaMesh unevenly across a model. Some pipelines skip UV texturing almost entirely for background props, exporting polypaint-baked vertex colours directly into the game engine's vertex colour channel, which is cheaper on texture memory but loses the ability to tile or reuse the texture on other assets.
