These 10 x 12 ziplock reclosable plastic bags with white block are the same very high quality as our plain 2 mil zips, featuring excellent seals and reliable zipper closures - PLUS - a white block for writing notes about the bag's contents. The dimensions listed are the interior dimensions of the bag. 2 mil plastic bags are our most popular thickness. These bags provide good strength without sacrificing clarity. They are premium, FDA/USDA approved, heat sealable poly bags that are excellent for storage or keeping your items clean and protected from moisture and dirt during shipping. The 100% virgin resin used to manufacture these bags offers moderate strength and clarity. Like all poly bags, the width represents the opening, and the length represents the distance from the opening to the bottom of the bag. Our ziplock bag length is calculated from the zip to the bottom of the bag, not including the lip above the zipper. The photo shown is an example of bag style only. Dimensions listed represent the actual size. Sizes are listed in inches.