3M Non-Printed Packing List Envelope NP3 is a top load, clear polyethylene, non-printed, envelope with a strong rubber resin adhesive. Custom printing available on all standard size 3M Packing List Envelopes. The 3M Non-Printed Packing List Envelope NP3 offers an easy to remove liner, exposing a high tack adhesive that holds packing slips, invoices, cards and other shipping documents securely to packages. This product features a natural rubber adhesive for good instant adhesion, and provides easy tear, while remaining pressure sensitive. Documents load from the back of envelope easily.