Our 18 x 20 6 mil White Block Clearzip® Locking Top Bags are heavy duty plastic zipper bags that feature a white block area for organizing, packaging, and storage items. The white block area on these 6 mil 18x20 18 inch by 20 inch 6 mil white block zip locking bags are made from low density polyethylene and can be recycled. These 6 mil white block Clearzip bags feature impressive clarity and make storage and organization simple for industrial, food service and medical industry applications. White Block Clearzip® Locking Top Bags are reclosable and resealable and meet FDA/USDA standards for use in food packaging and storage applications.