These are NOT strong and durable binders, they are inexpensive and suit my needs for organizing my kid's work. The first delivery I received, they were all bent, creased and misshapen, despite a box with absolutely no damage to the outer box. Amazon was really good about the returns, sending out new binders and not requiring me to return the destroyed ones. (it would have been a waste of postage, they were really a messand a waste of time I HATE having to deal with returns). The new ones were perfectly straight, not damaged at all, and were usable (though still not strong). I wouldn't use them for kids carrying around in a book bag, but I needed them for organizing their artwork and writings and I like the see through cover which I can slip an illustration into.