Don’t be afraid to get a little more creative!
Our partner stores won’t accept blank artwork – this means artwork that’s a plain shade of white, grey, or black.
This image is a plain shade of white/grey/black, so it wouldn’t be acceptable as artwork. 
This image is in greyscale, but as it’s not just one shade, it would be acceptable as artwork.
This image is a single shade, but it’s not white/grey/black, so it would be acceptable as artwork. 
This image has a plain white background, but the text means the image is not a plain shade of black/grey/white, so it would be acceptable as artwork.
If you upload a release with artwork that is just a plain shade of white, grey, or black, we’ll have to send it back to you and ask you to pick something else.
See also:
Does my artwork meet RouteNote’s quality standards?
Where can I find free images to use in my artwork?
Can I use deliberately out of focus artwork?