I've been googling all day, but I can't seem to find an answer to my question. I'm looking for a material that makes a distinct mark on contact with it's surface, but fades or can be wiped away. The contact will be made with a metal implement, not a marking implement (pen/pencil/whatever). I.e. the mark should come from the surface of the material. Also, the material should be strong enough not to tear with light pressure.
Any experts or "people in the know" want to shed some light on this mystery material? Does something like this even exist?