The paint builds up and you can toss the lid or peal the paint off. When you peal it off you have paint skin. Use care and ease the edges all around to help keep it from tearing. Now if you notice the side that was against the lid comes off with a sort of sheen to it.
Frugal is as frugal does, I keep those bits that are interesting looking and not too thick. They slice up pretty good or gentley tear into small bits and they glue down well.
They can make nice and unusual decorations for ATCs, journal pages and much more. Hey it keeps them out of the landfills too.
What kind of little things do you do that may be considered, by others, as too much of a penny pinching penchant?