Re: yellow pigment for gum

Well, this is good to hear, as I have made many prints with it. But Wilcox
was so castigating, saying, "As this is an imitation Gamboge I feel that it
should be described as such to remove any confusion. It should also employ
lightfast pigments for the sake of the customer." That, coupled with the
fact that M. Graham totally reformulated their gamboge to be PY151/PO62 made
me nervous. Have you talked with M. Graham about why they reformulated?
Chris

> 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,

> (Katharine wrote) 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 09:13:00 2005