Board Thread:Support Requests - Designing Your Wiki/@comment-1788837-20200520144438/@comment-9605025-20200520201009

Whether or not you can cover the entire background without tiling and without the vertical color break is determined by the image size. It must be at least 2000px wide. Whether or not you are allowed to use the image is determined by the file size. It must be 200 KB or smaller. If your image with 2000px or more in width but the file size is too large, you can try using an online compressor such as compresspng.