About the paper
The material has 7 layers:
1) Inner PE: easy to be hot seal
2) Adhesive PE
3) Aluminum foil: Trap light and air enhance the tightness of paper
4) Isolation layer PE
5) Basic paper layer: keep the sharpness of paper, as the basic layer for printing
6) Printing layer
7) Outer protecting PE: damp proof, dust proof, protect the printing