Many of us hams still use quite a few postage stamps. (We used to use a lot more.) It's not often that USPS produces a stamp series that directly applies to us, but they have one now called Solar Science.
These stamps are gorgeous. A photo doesn't begin to show how good they look because they're printed on a holographic type backing. When you move your head, the images change and animate, and the colors are iridescent and on a jet black background. #hamradio
I order mine directly from USPS. I find it easier than standing in line at the Post Office.