The Mylar material provides a light-weight but durable and flexible solution for packaging. Features and Information: For extended storage time, you can heat seal above the zip lock. The Mylar resealable bags tear notches enable access even after heat sealing. Package Net Weight: 0.4 lbs. PACKAGE INCLUDES: 100 premium quality 3" x 5" Stash Spot Mylar resealable Bags with Pressure Express Graphic on back. Materials: Front PET+PET+PE Back PET+VMPET+PE Thickness: 130 microns per side. MONEY BACK GUARANTEE – If you don’t absolutely love your Mylar bags return them to us unused and we will refund you the purchase price.