Artist Mitch O'Connell opened his ephemera vault to find his sub-collection of unusual vintage Valentine's Day cards. Below, a small sampling from his post.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects