Zipper Seal: Two interlocking plastic strips fit together to form a tight grip seal. This zipper seal creates a reliable closure that can be easily opened and then re-sealed. These bags are reusable thanks to the zipper seal. Durable: 4-MIL thick metallic foil provide durability and protects inner contents from UV and water vapor damage. Pack, transport and story without worry. Multi-purpose: Our mylar foil bags are suitable for ANY powdered or dry goods. Heat Sealable: Prolong the shelf-life of your product by heat sealing after filling. We recommend impulse heat sealers. Tear Notches:- Once these pouches are heat-sealed, they can be easily opened by pulling on one of the two tear notches. These notches allow the opener to cleanly open the package without stretching or creating a messy, jagged tear.Tear Notches:- Once these pouches are heat-sealed, they can be easily opened by pulling on one of the two tear notches. These notches allow the opener to cleanly open the package without stretching or creating a messy, jagged tear. Our Metallised Foil Zipper Stand Up Bag is a double sided metallised foil bag that is coated with a layer of matte/glossy for extra durability. The round-bottom gusset opens up when the bag is filled, allowing it to stand on its own. Enhanced with a grip seal, these bags are guaranteed to keep your contents fresh. If you need extra security, they can also be heat sealed above the zipper and re-opened from the tear notches found on the side. Also available in gold! NOT RECOMMENDED FOR LIQUIDS (WATER, JUICE), PLEASE TAKE A LOOK AT OUR HEAVY DUTY FOIL BAGS FOR LIQUID STORAGE.