Plymor Poly Mailer 2.25 Mil White / Gray Bag with Permanent Adhesive Closure and Perforated Tear Strip, 9" x 12" (Case of 1000)What size bag to order? Measure your item by its width, height, and depth because the bag needs to fit all the way around it. Item width + item depth = bag width. Item height + item depth = bag height.What is Mil? "Mil" is the plastic thickness. 2.25 Mil = .00225", slightly thicker than a standard zipper bag gauge.How to seal the bag? For your convenience, adjust the permanent adhesive strip to where the seal securely fits the product.How to use the bags? Our various sizes of Poly Mailer Bags are water and tear resistant and are great for packaging, shipping, or storage. They feature an adhesive strip that provides a permanent adhesive closure as well as a convenient, easy to open, perforated tear strip. These bags use up to 25% recycled content. You can package, ship or bag countless items like coins, pills, spices, jewelry, makeup, clothing, fashions, art prints, books or papers, collectibles, toys, game pieces, craft or scrapbooking supplies, merchandise for resale, electronics, tools, or hardware ensuring protection from dust, dirt, and moisture.