Setting things straight about Parker Quink

It seems the battle against misinformation is never-ending. Once one old collectors' myth is put to rest, new ones arise to take its place. I've recently noticed a sudden upsurge of confused factoids about Parker inks in the fountain pen groups on Facebook. Inks are rather outside my main areas of research interest, but I know enough to be able to see a problem in the making -- so let's set things straight before they get totally out of hand.

First, when we're looking at Parker ink production from the 1930s through the 1950s, we're talking about three product lines: Quink, "51" ink, and Superchrome. Quink is the oldest of the three, and the only one still in production (with minor reformulations). Quink was introduced in 1931; despite what the confused Wikipedia article states (at least, until I can get a chance to correct it [now corrected; let's hope no one changes it back -- D.]), Quink was a mild ink that would not harm pens such as Parker's top-line Vacumatics which held their ink directly within celluloid barrels, as well as models such as the Challenger whose sections featured transparent celluloid ink windows. 

The strongly alkaline pH balance and isopropyl alcohol content that distinguished "51" ink were NEVER features of Quink. The Parker 51 and "51" ink were developed in tandem, the pen designed specifically so it would be able to hold up to its special caustic ink. The ink was explicitly promoted and sold as suitable only for the Parker 51. Parker openly stated that it would clog and damage pens not specifically made to use it. "51" ink was introduced in 1941, and was replaced in 1947 by Superchrome -- a somewhat milder but still corrosive reformulation, similarly marketed for use exclusively in pens made to use it: the Parker 51 and its budget offspring, the Parker 21. 

It does appear that there was an initial release of "51" ink as "Double Quink" (discussion here), but I very much suspect that this took place only as unadvertised market trials done as part of the well-documented market trials of preproduction Parker 51 pens from 1939 on. It is telling that I have yet to see a photo of an actual surviving Double Quink bottle, and that David Shepherd was unable to come up with one for his Parker 51 monograph despite years of diligent focused collecting and free access to Parker's own archives.

ADDENDUM: While rewriting the Wikipedia article on Quink, I took a closer look at the apocryphal story that Quink had been invented by and named for a Filipino chemist, Francisco Quisumbing. While clearly false -- the details of the development and naming of Quink have been thoroughly documented -- it was puzzling how such a story could have arisen in the first place. As it turned out, a Francisco A. Quisumbing had in fact founded a successful ink company in the Philippines in 1923, a few years after completing his Ph.D. at Columbia University. The basic biographical details appear in the 1937 volume of Who's Who in the Philippines, pp. 128-29. Quisumbing contributed the preface to a 1960 book, Forensic Chemistry of Ink in Documentary Investigation, by Paul R. Verzosa, in which it is mentioned that the Quisumbing Ink Products company supplied all agencies of the Philippine government under an exclusive contract (p. 22).
I was also able to find mention (and dismissal) of the Quisumbing/Quink myth in a book published in 1999, so the story has been around for a good long time (Virgilio L. Malang, Inventions & Innovations: A Glimpse of the Filipino Legacy, p. xiv).