What's the best way of preventing an envelope from being folded?
May 20, 2016 8:17 PM Subscribe
I sell slim graphic novels by mail. They are 8.5 x 11 inches. What's the best way to prevent the post office from folding them in transit? The obvious idea is to put a piece of thick cardboard in with it. But I want to minimize shipping costs. What would be a cool way of doing that?