shipping at Additional Charge to ALASKA HAWAII , PUERTO RICO OTHER EMIRATE archival storage display cello clear cellophane envelope , sleeve bag 10 - Cellophane ENVELOPES Archival Quality Acid Free LIGNIN FREE FLAP SEAL - REASEALABLE 2 PCS 5 X 7 ENVELOPES 2 PCS 9 X 12 ENVELOPES 2 PCS 11 x 17 ENVELOPES 2 PCS 12 x 16 ENVELOPES 2 PCS 13 x 19 ENVELOPES Actual size 5 X 7 - A7 -- 5 7/16 X 7 1/4 + FLAP 9 x 12 + 9 1/4 X 12 1/8 " plus flap 11 x 17 + 11 7/16 " x 17 1/4 " plus flap 12 x 16 + 12 7/16" x 16 1/4" + Flap 13 x 19 + 13 7/16 x 19 1/4 PLUS FLAP ACID FREE - LIGNIN FREE 1.6 MIL 40 MICRONS THICKNESS What It Means To Be Acid and Lignin Free Majority of Scrap Bookers have heard the term ?Acid and Lignin Free?, but what does this really mean, and why does it matter? Acid free materials have a pH balance of 7.0 or higher. The pH scale measures how acidic or basic a substance is. The scale runs from 0 to 14, with 7 being neutral. Anything with a pH less than 7 is considered acidic, and anything over 7 is considered basic. Lignin is a natural occurring bonding element in plants that holds the wood fiber together. While lignin is not an acid, it does give off acids as it deteriorates. Therefore if you have a paper that is only acid free, but still contains lignin, it will become acidic over time. 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. Do not automatically assume that because an item it purchased in the ?scrapbook? section that it is photo-safe. If it does not say ?photo safe?, ?acid-free? or ?archival safe?, assume that it is not. A pH pen can be purchased to test the acidity of a product if you are not sure. Our top selling Crystal Clear Flap Seal Bags are ideal for art, photo, stationery, bulk mail, craft hobby, and just about anything else. These bags have optimal clarity and durability. Adhesive strip is on the flap. USPS Approved. Details Crystal Clear Flap Seal Envelopes have the following features: ? Crystal Clear Optical Clarity ? High quality material will not easily rip, tear, wrinkle, or fog ? Acid and Lignin Free ? Archival Safe ? USPS Approved ? 1.6 mil thickness ? Adhesive on the flap allows you to customize the fit ? 10% Recycled Content ? 1/16? size tolerance ? Envelope sizes indicates the opening side as the first dimension A great way to showcase Your Magazines Collectibles AND GREAT FOR STORING YOUR PERIODICALS DOCUMENTS or PHOTOS ARIZONA HIGHWAYS MAGAZINES , DESERT MAGAZINE , NEW MEXICO MAGAZINES YOUR OTHER VINTAGE MAGAZINES AND COLLECTIBLES MAGAZINES NOT INCLUDED 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 shipping at Additional Charge to ALASKA HAWAII , PUERTO RICO OTHER EMIRATE