I have done background removal on basic images but I'm having trouble when shadows come into play. I've uploaded an image of a label. I would like to place it on an object using a layer mask. It's got some holes in it. What's the best way to get rid of the background that shows through where the holes are located? I want to get rid of the white background and any of the shadows in the image.

Thank you very much for the help. The image was given to me by a friend. It was pulled from a search engine. Re-scanning was not an option. I'm not exactly what you would call a GIMP "power user". I'm familiar with most of the basic functions but that's about it. I spent quite a while trying to find the right tutorial. I would probably still be pulling my hair out if you hadn't created the post.

Looks like a scan, if possible rescan with a dark card background rather than the scanner white cover.

You probably found that the usual fuzzy / color select does not work too well, neither does making a mask using threshold.

Back to bad-old-ways using the image in indexed mode. Does not work with all images but will with your map.

Two and a half minute demo: https://youtu.be/BNYz9oYwKwI