Whiteboard
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. Dry-erase markers for whiteboards were invented in 1975.
Blackletter
The "Donatus-Kalender" (also known as Donatus-und-Kalender or D-K) is the name for the metal type design that Gutenberg used in his earliest surviving printed works, dating from the early 1450s. The name is taken from two works: the Ars grammatica of Aelius Donatus, a Latin grammar, and the Kalender (calendar). It is a form of textura.