The U Mark AP-1 marks almost any surface and dries within 10 seconds. Its tip is reversible so that both its round as well as its chisel shaped ends can be used. A pressure valve regulates and controls its ink flow. The AP-1 is exceptionally well suited for use on waxed cardboard, packaging film, packing tape, cardboard and labels, but also on polypropylene, polyethylene, rubber, precast concrete slabs, glass, wood, greasy materials and ABS plastics.