The inner layer is made of food grade PE, and the outer layer is high-quality kraft paper, our reusable stand up bags are an excellent choice for your food storage needs. We have many sizes you can choose. Our kraft bags are sturdy, have a strong seal, and feature a transparent window to view the contents. The stand up pouches for food storage are easy to fill thanks to their ability to stand on their own. A non-waxy surface that is easy to label with stamps, stickers, markers, etc. Because the kraft zip lock bags for food storage are made from food grade materials, you can trust that coffee, candy, rice, sugar and spices, nuts, and more are safe for long term storage. There is a advertising space above the window, you can add stickers or labels on it.