Formula Werks is celebrating Summer with their traditional Secret Stash. For 2010 the stash features limited-edition tees from (clockwise above): Jim Mahfood (LA), Tree House Press (UK), Ken Keirns (BAY), Angry Face (CHI), and Jim Koch (WA). Each of these tees comes with a button pack and sticker pack and is available for preorder at premiumstash.com for $28 each in both men’s and women’s styles. Orders will be accepted until May 30th – after that you’re out of luck. These premium tees printed on super soft shirts with water-based inks will ship on June 15th 2010.