I use the Johnny Cash stamps for bills, to cover up the “Put stamp here” on the envelope and not show through.
I love to send a message with these stamps. If I would pay a charge card bill to weakling lib companies like Macy's (I don't patronize any of 'em) or any of my dopey liberal friends (I don't have many of 'em) I'd use the American flag stamp on one side, my red, white and blue Disabled Vets address label on the other...and I also affix one or two patriotic sticky things I have in my stash on the back that I think would irritate them ...including my liberal Dem mailman, LOL.
Leni