Self-adhesive packing list envelopes are widely used in logistics/express 　industries, they feature a wide variety of standard sizes and styles for different markets. They also can be custom produced and printed. They are made of sturdy polyethylene (PE) or Polypropylene (PP) film in clear or white. Utilizing hot melt adhesives that stick well to cardboard, plastic, wood, glass etc., they can hold documents such as packing slips, invoices, operation instructions etc.