1,sealing,fastness,good security,handy use. 2,Good Quality Courier bag 3,mailing usage 4,mail,courier bags 5,Courier use Introductions:Mailing bags, also named Mailing envelopes courier bags,experess bags,mailing bag.1.Material:LDPE.2.Film Colour: outside-white & inside-black.TIANBAI PLASTIC3.Type: side sealed bag.Film can be extruded from same material or different.4.permanent adhesive tape on ...