Paper and typography are two of my favorite things. I think sometimes that maybe I should have majored in graphic design in college. Alas, I don't think it was offered or you had to go through the art department or something.
Nowadays I get my fill from looking at the wonderful invitations and paper goods that talented artists have created. These are perfect examples of what you can do for your summer picnic wedding. I'm thinking casual, but still gorgeous stationery, suited perfectly to fit your personality.
Photo via Serendipity
Photo via 42 Pressed
Photo via Summer Picnic Wedding