Maybe I lack imagination, but I don't see how that can keep a high grade comic high grade if there is some rough handling. I would be terrified shipping a $50 nm type book in that.. That's like mailing a comic out with 2 pieces of cardboard as the sandwhich, which I would never do unless maybe industrial thickness cardboard, otherwise minimum 3-4 depending on thickness. Regardless, I am shifting to boxes and the genesis type mailers. And I understand, you haven't had a book get damaged, but maybe you haven't encountered the right postal worker in the wrong mood? heck, I used to ship records in bubble mailers (because they were "free" at my office) like 18 years ago, but that makes no sense. Somehow out of like 75-100 records mailed, none got cracked in half. In hindsight, I got very lucky.