Die-cut, crush resistant paperboard mailer make assembling quick and easy without tape, staples, or glue. Shipment should be sealed with a tape. Mailer made of corrugated paperboard is very strong yet lightweight. There are double walls of protection on the front and sides of crush-resistant mailer. The corrugated sides make mailer extremely strong. The crush-resistant paperboard made packaging material is delivered flat in bundles. It can be availed in custom sizes to pack important documents and other essential items.