Storex Thicker Poly Two-Pocket Folder with Plastic Prongs, Black, Case of 18 (STX50316U18C) Poly folder holds 20 sheets; case of 18 black folders Flexible and fits in a backpack with ease All-plastic prongs are safer to use than standard metal clips Thicker material than standard poly folders and report covers; will not tear or fray Reusable - lasts much longer than cardboard portfolios