First celluloid pens

Those who know a bit about fountain pen history will tell you that Sheaffer was the company that pioneered the use of celluloid. Those who know a bit more will tell you that LeBoeuf beat Sheaffer by a few years, though it was Sheaffer's adoption of celluloid that was responsible for the industry-wide move away from hard rubber that quickly followed.

What very few realize, however, is that celluloid was used by other penmakers well before either LeBoeuf or Sheaffer. Indeed, by the 1920s celluloid was already an older material, widely used for all sorts of articles since the 1880s. Serious pen history geeks will recall past discussions of the 1909 article in The Metal Industry in which electrodeposition of silver overlays is described. The third paragraph of that article begins, "The pens, being made of hollow rubber or celluloid . . ."
I suspect that any overlay celluloid fountain pens made this way were of the cheapest sort, but I have also personally handled name-brand celluloid pens with non-electroformed overlays, including at least two Parkers, as well as a non-overlay John Holland hatchet-filler. The celluloid parts of these pens were all black, and could easily have been mistaken for hard rubber. But I have also seen small colored celluloid  pens made by Salz, some with parts marked "GERMANY", datable to the early 1920s, about which I posted here back in 2013.

There are yet earlier European celluloid pens, too, though they are of truly execrable quality and design. I am speaking of the Manos, a dirt-cheap Austrian-made piston-filler that was also exported to different markets as the Standard, the Triumph, the Globe, and the Victoria, among other names. Advertising appears well into the 1920s, but the first American mentions I've found date to 1912 with other writers reporting appearances as early as 1904 in the British trade press.