9.) 100 - 6 x 4 x 3" Corrugated Mailer-- Corrugated mailers are super strong yet lightweight to save on postage expenses. Perfect for shipping small, lightweight, fragile items. Each corrugated mailer is manufactured from 32ect-B oyster white corrugated. Crush resistant mailers fold to provide double walls of protection on front and sides. Our unique Ã¢â‚¬Å“wave ruleÃ¢â‚¬Â edge virtually eliminates paper cuts. These one piece mailers fold together in seconds. No tape, glue or staples needed. All ship and store flat to save space.