I'm very fond of this recent stamp release from the USPS, featuring beautiful examples of industrial design.
The works and designers featured in this stamp set proved that form and function could be perfectly married, and the stamp set itself has a nice, clean, modern design.
Other reasons to pick up a few sheets for your holiday cards: they're great for using after the holidays, too; they're "Forever" stamps, so they'll cover the first class cost of mailing a letter indefinitely (stock up!); and they speak to a vintage design aesthetic that's very current, making them a great choice for designers' business mailings.
* I'm not compensated for my reviews of various design products; I just like to call attention to things I think are beautiful.
Photo credit: USPS. Photo is used here for the purpose of review, and links back to the purchase page for this stamp set.
(p.s. you can make these photos bigger by clicking on them . . . but you probably knew that!)