I probably need to stop collecting invitation ideas soon

Brilliant handkerchief invites by printing custom fabric with a square map design at Spoonflower and then cutting up the fabric to make handkerchiefs.

I've always really liked clean line drawings, like Danny Gregory's. Every so often I try to get into sketchbook journaling because I'd like to be able to document surroundings like this (Oh So Beautiful Paper)

Amazing laser cut gatefold, closed with a wax seal by Paisley Quill, via Oh So Beautiful Paper. I think this could be translated to a really cool design with red Chinese papercuts. Which I've totally posted about before, heh.

Simple but clever printable mailer template from Lisa Rupp for Gifted Magazine, pg. 129.

Envelope template from Melissa of IS•LY

Also not a specific design but something that may be useful: design*sponge's favorite fonts roundup.