25 10X13 Poly Mailers Black & Silver Stars Thank You Flat Mailers PRICE IS FIRM 10x13" Standard Size Premium Designer Printed Shipping Mailers. Our Special Blend of Polyethylene Creates an Extra Strong, Flexible, and Tear Resistant Bag, While Being Super Light Weight, Reducing Shipping Costs, and Being more Eco Friendly. These Bags Ideal for Quickly Shipping Clothing, Pants, Jeans, Leggings, T-Shirts, and Many Related Items. Permanent & Strong Self Adhesive Strip Allows for Quick & Secure Packaging. 100% Non-See Through.