Metronic 200 Pcs 9 x 12 White Poly Mailer Envelopes Shipping Bags with Self Adhesive, Waterproof and Tear-proof Postal Bags PROVIDES CONFIDENTIALITY - These poly mailers were white outer surface, black inner lining, so it looks like light grey color not a true bright white. The Mailing Bags used of opaque materials convenient for protect your privacy with a professional appearance. WIDELY USE - The 9x12 mailer bags are quite useful for soft items, such like T-shirts, blankets, scarves, or other non breakable items. They are definitely quite durable and the sticky strip sticks very well. WATER PROOF - The poly mailer are self-sealing for easy packing with a tamper-evident, super secure closure. Pressure sensitive adhesive provides a high strength, durable closure that is water and dirt resistant. The Plastic Mailing is thin, durable, and quite flexible, so they're very forgiving of weirdly-shaped contents, and it's easy to add in a bit of padding, like newspaper or bubble wrap, for extra protection. DURABLE PROTECTION - Top-quality poly mailers are tear and puncture resistant. Even though poly mailers don't offer interior cushioning, they are made to withstand the rigors of the shipping process. A poly mailer is usually made of polyethylene but can also be made of heavy-duty nylon fibers. Poly mailers are a great choice for their high-strength design that keeps contents secure against moisture, chemicals, tampering, puncturing and tearing. SAVE YOUR TIME AND SHIPPING COST - The poly mailer bags are good acceptable thickness for shipping soft-goods, and they are light enough to safe you some money on weight for shipping. The white mailing bags have a peel-off strip that is very sticky that will seal the bag very well, it's quick seal, no licking or water needed. The poly mailer bags are a good strong plastic shipping bag. If you have many orders need to post everyday, these plastic mailing bags perfect for you!