> There is Hansa and there is Hansa and...
Here is a story about "Hansa":
Puzzlement over info dissonance re Permanent Yellow permanence brought
the name "Joy Turner Luke" to my mind. She is big color authority in this
country whom I had I met when she stayed here for Pratt color conference
some years ago. I telephoned, she was most gracious, & so full of info I
could hardly take notes fast enough.
She promised to send me some relevant printed matter & I await more
precise data from Rowney, so I won't speculate about R. P. Y. at this
point except to say her general reaction was, "Wilcox is pretty good," she
helped provide some of his info (Joy was herself president or whatever
they call it of ASTM for a while), but arylide G is also pretty good, she
said, & the Wilcox quotes I quoted seemed "exaggerated."
In any event, it seems arylide (which I had pronounced arry-leed, she
pronounced are-ya-leed) is exactly our old friend Hansa yellow. The
pigment, she said, was originally made by the German firm Hoechst and
marketed world-wide as Hansa yellow until World War I, when it could no
longer be imported into the US. At which time Hoechst stopped defending
its trade name here, and "Hansa yellow" became a generic term, freely used
by other companies. In Europe, however, it remained a trade name &
couldn't be used by others.
Now, apparently, post-WWI, Hoechst again defends its trade name in the US,
and so others have to call the same/similar/related pigment "arylide."
There are, as Luis says, many arylides, and to complicate matters further,
their "archivality" varies with the medium -- acrylic, oil or water color
-- and, presumably, gum.
Luis's advice may well be the best course now -- make your own damn test
*of actual use conditions* (like any of us needs another test). I don't,
alas, have a sunny window (look, this is NYC) tho I have gotten distinct
messages from exposure on sill of north-facing window & will try that
approach again.
Meanwhile, one of the other things Joy said was that the color index names
were developed in England, so they are colour index names.
^
Cheers,
Judy