Black chased hard rubber was one of the mostly commonly used materials for fountain pens in the early years of the 20th century. Chasing refers to the pattern imprinted on the pen.

"Hard" rubber, made from vulcanized rubber originally developed by Charles Goodyear in 1844. The name comes from its intended use as a substitute for ebony wood, and was the material used in most of the earliest fountain pens.

A lever-like device shaped like a hatchet so that the protruding end goes through a slot in the barrel and depresses a pressure bar to fill the pen. Thus the filling system like a lever filler, but the "lever" is flipped completely over for use. The hatchet-filler was introduced by the John Holland Co. in 1915."

Introduced by Sheaffer in 1912, the lever presses against a pressure bar which depresses a sac to fill the pen. Lever-fillers became the dominant fill mechanism for Sheaffer, Wahl and Waterman from the '10s through the '30s.

A Waterman from the '40s that featured a hundred year guarantee. They were offered in three sizes and several colors, and with smooth barrels and those with distinctive concentric ridges.