CLEAR ARCHIVAL STORAGE ENVELOPE ACID FREE RESEAL 20 PCS CRYSTAL CLEAR 16 X 20 16 X 20 3/16 THICK ACTUAL SIZE 16 1/4 x 20 1/16 PLUS FLAP PLEASE ALLOW FOR THICKNESS Cellophane Archival Quality Acid Free 20 pcs - Resealable Envelopes 16 X 20 16 X 20 3/16 THICK PLEASE ALLOW FOR THICKNESS PROTECT YOUR COLLECTIBLE ART , POSTER , DOCUMENT BOOK , MAGAZINE OR NEWSPAPERS ACID FREE = QUALITY STORAGE 20 Pcs - 16 1/4 x 20 1/16 16 X 20 UP TO 3/16 " THICK PLEASE ALLOW SPACE FOR THICKNESS Cellophane Envelope Bag Sleeves " RESEALABLE ENVELOPES " Crystal clear with resealable self adhesive sealing strip that protects the contents from dust, bugs, moisture, and mildew. 1.6mil (40 micron) thinkness archival quality. with a unique crystal clear solution, provide 'Retail Pack' appearance and beautiful finished look for your product. These bags are made of Polypropylene( Cellophane envelopes / Cello bags ), it is an all together different resin than Polyethylene( Poly Bags ). Cello bag is non-porous, super-clear, non-stretching and generally stronger and more rigid than Poly bags. This quality is commonly used for displaying merchandise at retail. THESE ACID FREE ARCHIVAL STORAGE ENVELOPES ARE OF THE HIGHEST QUALITY , THEY ARE EVEN FDA/USDA approved for food use. Shipping parcel post or priority mail package or flat rate envelope 200 SIZES AVAILABLE UP TO 60 X 40 INCHES IN SIZE all returns are subject to a 20% return / restock / handling charge , any return will also forfeit any multiple item discount for other item purchased at the same time when applicable envelope , bag , sleeve , flap seal , acid free , lignin free crystal clear 75 sizes in stock ready to ship , over 200 sizes available Features Benefits: Crystal Clear Flap Seal Envelopes have the following features: Crystal Clear Optical Clarity High quality material will not easily rip, tear, wrinkle, or fog Resealable adhesive strip on the flap of the bags (allows you to customize the fit) with the exception to the Protective Seal where the seal is on the body of the Envelope which leave little for adjustment Fast insertion and sealing Acid and lignin free Archival safe 1.6 Mil / 40 micron thick USPS approved Made with 10% recycled content Acid Free , Lignin Free , So why does all this matter? Simply put, acid and lignin cause paper to deteriorate. A good example of this is newspaper. You will notice that after only a couple of days, newspaper begins to turn yellow and brittle. The same will happen to your scrapbook and photographs over time if the proper materials are not used. These materials do not only include paper? adhesives, pens, markers, stickers, and anything else that comes into contact with your photographs must be acid and lignin free. AVAILABLE IN SIZES UP TO 60 " X 40 " 1.6mil (40 micron) thinkness archival quality. PLEASE ALLOW SPACE FOR THICKNESS We may use UPS , Fedex in place of Fedex UPS and USPS to Select Service areas at Our Discretion to improve Delivery ServiceBuyers with - 0 - feedback and less than 1 year will not be eligible to purchase and may be refunded