General description These metallic blue mailing bags are manufactured from heavy-duty polythene, making them both durable and economical. They are designed to help your goods stand out while providing reliable protection during shipping. Technical specifications Dimensions: 16" (405mm) length x 12" (305mm) opening Thickness: 55 mu Opacity: 100% opaque (black from the inside) Seal: Permanent seal with a 40mm lip