I bought these to organize my scrapbook paper, I prefer these to a large box with built in folders as I can grab what I need and take it to a crop without taking my whole box. The plastic is clear and sturdy. They have a tab on top so you can label what kind of paper it is.
I own many many of these. I use them to keep my paper collections together, my vellum nice and neat and my kits together. It's so convenient to just pull out of these folders to work with. I am able to fit about 6-7 in one vertical file