Durable 3-ply spiral wound mailing tubes construction protects sketches, blueprints, graphs, posters, important documents, etc. Vibrant colors make a professional appearance when mailing your important documents. Plastic end caps are friction-fit to stay on during mailing. The flat cap surface is ideal for writing. High quality with superior crush strengths. ID 18mm to 850mm Wall thickness 1mm to 35mm Liners available in white, black, custom printed, etc. Smooth, burr-free blade cuts. used 100% recycled paper paper board Volume discount pricing