Etsy is a great place to find handmade or vintage items. I'm a regular shopper there, as I love both supporting artists and finding unique gifts. I began searching the massive Etsy community for science-inspired artwork, and I found the most amazingly robust and beautiful science t-shirt shop, nonfiction tees.
The shop is run by designer and self-described ninja printmaker Ryan Aydelott, who has worked in computer sciences, graphic design, as well as fine art. I asked Ryan what inspires his amazing science t-shirts: "I have always worked in the sciences - and really just designed things I liked, using a lot of old educational imagery and other related items that I just found beauty in."
I think his t-shirts speak for themselves!