When was the dry-erase marker (used to write on whiteboards) patented?

Two men have been credited with the invention of the whiteboard. The first is a Korean War veteran and photographer named Martin Heit and the other an enameled steel production company employee named Albert Stallion.

Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board.

The whiteboard pen (also called a whiteboard marker or dry erasable marker) was invented by Jerry Woolf of Techform Laboratories and later patented by Pilot Pen in 1975. It is a non-permanent marker and uses an erasable ink that adheres to the writing surface without binding to or being absorbed by it. Unlike permanent markers, erasable ink does not contain the toxic chemical compounds xylene and/or toluene.