Re: yellow pigment for gum

Christina Z. Anderson wrote:
>
> Katharine,
> I'm working on a chart of the yellow pigments I have used in gum (10 of
> them, painting swatches side by side). I notice that Wilcox gives the M.
> Graham old gamboge which was PY110 a not lightfast rating (p. 68 2001-2
> edition of Wilcox Guide to Watercolor Paints).
>
> Obviously this is a moot point since M. Graham reformulated their gamboge,
> but I notice in my notes that this was a yellow you used, or used to,
> anyway,

PY110 is and always will be my favorite yellow pigment; with the recent
discovery of a cache of the old Graham PY110 in a local art store, I may
have enough of the Graham to last the rest of my life; if not I'll
switch to Daniel Smith.

so:
> 1. Do you think Wilcox is wrong?

Yes, as he often is.

> 2. If one author says it is not lightfast but another says it is, do you
> err on the side of caution?

No, as I have said several times even in the last week, when there is a
discrepancy I always go with MacEvoy, whom I accept as the ultimate
expert and who rates both the M. Graham and the Daniel Smith PY110 at
7,8, (8 being the most lightfast possible) and adds "The ASTM (1999)
rates this isoindoline yellow as having "excellent" (I) lightfastness;
manufacturer and industry tests agree, and it may be the most lightfast
deep yellow pigment available."

> 3. Have any of your PY110 prints noticeably faded over the years?

Nope.
>
> I'm contemplating throwing out the paint because there are a couple other
> yellows that are similar.

I don't have anything invested in this pigment and won't be offended if
you throw it out. I personally know of no similar pigment, that is at
one and the same time a beautiful bright deep yellow and is also
totally lightfast and totally transparent. But I'm testing some other
yellows when/if the Daniel Smith order comes, and perhaps I'll change my
mind. But I'll be surprised if I do.
 Katharine
>
> Chris
Received on Mon Jun 6 08:43:48 2005