After a futile attempt to get some of the small Priority Mail boxes at the post office, I was told by them that they no longer carry the small boxes, but you could get them on-line. (Huh?? The post office doesn't carry their own supplies anymore?? I thought that was kinda weird.) Anyway, if you go to the link below and hunt around, you'll find those priority mail boxes. They're FREE. I think you have to get 25 at a time, tho. They're actually called video boxes or something, and the larger of the two is probably a good size to get. The smaller one is about the dimensions of a sheet of paper folded in half, and about an inch and a half deep, and the larger one is a teensy bit bigger and deeper. FYI for all of you sending round robins and such all over the country.