The seams take away quite a bit of space so that we had to go back and buy a bigger envelope to put in a book even though when I placed the book on top there were inches to spare. One must make allowances for about an inch or more all around.
For several years I have used your bubble wrap mailing envelopes to send heavy cardboard-backed wall calendars to people here and abroad. I've never had a complaint about one being damaged. Many thanks for a fine product. Anne Thomas