These self-seal 9" x 12" White plastic Mailers are the perfect packaging material to protect your products from moisture during shipping while also setting your business apart with a clean white style. Just add your custom label. White Shipping Mailers envelopes are Moisture resistant, Puncture resistant, Tamper evident and Tear resistant. The inner lining is silver which further blocks the contents you have packaged. 9 in x 12 in .0025 Poly mailer envelopes are commonly used for shipping a wide variety of individual goods like t-shirts, textbooks, jackets, toys, arts and prints, fabrics, and more.