UV Seam
Where a UV island is cut
Also known as: Visible seams · Texture seams · UV cut · Seam in texture · UV seam fix
Quick answer
A UV seam is the edge where a UV island is cut so a 3D surface can lay flat, and visible texture seams appear when the textures on each side of that edge do not match. The usual causes are too little texture padding, different texel density on neighbouring islands, and a mismatch between smoothing and UV splits. Hide seams along hard edges or out of sight, keep texel density equal, and use enough padding.
How to fix it
Place seams where the eye does not go: under objects, along existing hard edges, in panel lines. Keep neighbouring islands at the same texel density, and give each island padding so colour continues past its edge and mipmaps do not pull in the background. Do the final texturing in a tool that paints across seams, such as Substance Painter. Bake normals with the same hard and soft edge setup you export with.
