It is made of 50um thick transparent PVC plastic film. Forms are printed in the white area on the surface and can be written with a ballpoint pen. Plastic material evidence bags can hold wet and oil-soaked material evidence. Plastics have good transparency and can easily observe physical evidence from outside. The opening of the material evidence bag is sealed with sealing tape. After putting the material evidence into the bag, the opening is sealed with sealing tape. The sealed material evidence bag can not be opened without damage.