I’ve had a lot of luck in my classes with these zipper supply bags. The ones I purchased were from Dick Blick and I was originally concerned that the zippers would not hold up. A couple of year later they are in good shape even with daily use. One had a zipper tab fall off…just the pull tab, which can be replaced with a piece of cord or something. A handful were abused by students but only cosmetically damaged and still function fine. Overall, I consider them them indispensable.