Our 21" x 30" 4 Mil flat clear plastic poly bags on roll are good for packaging heavy weight items for added protection of food, parts, hardware and more. All 21x30 4 mil polybags on roll are made from low density polyethylene and can be recycled. These layflat 21" x 30" .004 plastic bags on roll feature impressive clarity, durability and make storage and organization simple for industrial, food service and medical industry applications. These heavy weight plastic lay flat 21 inch by 30 inch bags on roll are perforated for easy tear off and can be sealed by using twist ties, bag tape or by heat sealing, and they meet FDA requirements for use in food packaging and storage applications.