cratch Pen Wire Tips Replacement (2) The wire-tip tools are made of high-strength stainless steel for long-lasting performance. Scratch Pen is an excellent and useful tool for incising and excising a design directly on leather-hard clay works. The double-end interchangeable wire tips are made of high-strength stainless steel wire for long-lasting performance while the soft silicone handle to provide artists an ultimate comfort experience and a pleasure to work.