I have 3 mint stamps with mottled gum on the back. Originally I supposed that these were storage issues or partially used, but uncancelled, etc. However, I was going through a large batch of mint stamps, and found 3 of them with these "splashes" and one with full mint.
a) Is anyone else aware of it?
b) Are there people who would be interested in these stamps? I know people will collecting tagging variations, but wasn't sure about gum errors. I'm willing to share free, but would love to know why, too.
Thanks for any feedback!
P.S. It's hard to photograph it to show the gum difference, though I will if needed.