PaknSeal Self Seal Poly Bags with Suffocation Warning, Strong Adhesive Clear Strip (9 X 12) Meets Amazon's packaging requirements - 1.5 MIL Easy to use Peel and Seal Adhesive Closure for Quick Packing The bags are made from a high quality polyethylene (PE) that are slightly stretchable to keep products from tearing the bag. The adhesive strip is extremely sticky to prevent unexpected opening. Poly bag comes pre-printed with a suffocation warning in English, Spanish, and French.