I have been using this product for many years to send out photographs to be autographed and the envelopes generally hold up well even with the rough treatment our postal services gives large envelopes. I use tape or glue as an added precaution the flaps do not become unglued (altho this has never happened I don't want to take any chances). I have tried other type of envelopes but the seem too flimsey and the bottom flaps are always half torn off which could cause the photos to get damaged. I also use a cardboard stiffener to prevent the photos from being bent since the postal worker likes to see if they can roll it into a tight ball to fit in my mail box the stiffener prevents this most of the time and the envelope stays in tact.So to sum it up good product at a reasonable price.