I buy several dozen of these at a time. Another use I have found for the zipper bags I purchased from Dick Blick is for individual supply storage for students. I created a laminated, numbered insert for each bag that corresponds to a seat/table in the classroom. Each student is issued a bag for the year and they are easily distributed at the beginning of each class on days when those supplies are being used. They typically contain a hard-lead pencil, eraser, and project-specific supplies like scratch-art tools or a felt pen. I use a supply tub rack system for sorting the bags by class.