Inner is protect humidity-proof wax paper ,Mdeium is plastic film, Outer is sackcloth or compound paper packing. 1.Steel Strapping, for binding and packing of wood,paper,glass and steel.2.steel strapping is made from ordinary carbon structured or high quality carbon structured steel via cold-rolled, electric heat and blue. it is applicable for bundling and packing of wood, paper, glass, stone, ...