Not only that, but you need enough padding between your uv islands. If your islands are only 1 pixels apart it will work at 2048, but mip down to 512 or even 1024 and you'll start to have issues. Good rule of thumb is probably about 16 pixels between uv islands at 2048, 8 at 1024, 4 at 512 or so. Also, if you have a black…