... that does not need protections. Unlike other Shipping Supplies, Poly Mailing Envelopes do not contain any bubble, foam or paper cushioning. Our ... to ship clothes, bathing suits, shoes, books, magazines, etc. Plastic Mailing Envelopes come in a wide variety of thicknesses, colors, and sizes ... the way up to 26" x26 ". The size of the Mailing Envelopes are typically the actual usable area. PM3 7.5x10.5 ...