Multi-tile UVs are exackalackaly what you need! Put a UV island on each tile (0-1 UV is considered one tile), make the size of each tile's texture be 2k or 4k, and paint them with a tool that supports it well. http://store.steampowered.com/app/289550/ ^ Good painting tools, layer system, and shaders, up to 6x 4k textures…