... resistant c.customized size,logo d.Waterproof & recycle plastic postage bagscourier bag and mailing bag, express delivery bag, mailer bag, post envelope: materialLDPE or HDPE coextrusion ... control with ISO9001:2008 quality certification, anti-static and shockproof. 7.kinds of raw materials: PO, PE, OPP, PP, PVC, CPE ...