Very sturdy but it is difficult to get into the backpack. It is wider than average and the edges catch on the sides of the backpack making it hard to get in and out.
I dread going to the store to buy binders because they have become so expensive but these are definitely worth the money. They've lasted longer than any other binder I've owned and they're perfect for my loose leaf books for school.
I use this binder to put in the chapters I'm studying from my looseleaf version of a textbook. It feels very sturdy but the sides look like it would rip.