U of S | Mailing List Archive | alt-photo-process-l | RE: archivalness of gum

RE: archivalness of gum

> I'm going to assume that what you meant to say was that 
> today's "indigo" is a convenience mixture; you didn't really 
> mean to say "today's indigo is a mixture of prussian blue and 
> quinacridone  
> red."   The statement that today's indigos are convenience mixtures  
> is a true statement that I can agree with;  why don't we just 
> leave it at that.

That I agree. It went through that stage at one point, but then of course
prussian blue was found not to be that stable either, so prussian blue was
later pretty much replaced by thalo blue or thalo blue mixed with black. I
agree that when I said "today," I probably have "later" in mind, and
nowadays indigo is a mix.

> Also, I don't always read everyone's posts.  I 
> was going on the belief, from some fragments I'd seen here 
> and there, that the discussion of hue names started with a 
> conversation about  pigments relating to  a book about gum 
> printing, which is where I got the idea that it had  
> something to do with gum printing.   My mistake.

Actually I don't read all messages either, so it is true that I wasn't sure
(and still didn't go back the check) what the original thread was about. I
just saw Judy's message about gamboge and lakes, so I branched off with
that, more like a fun facts kind of things on how "pigments" or pigment
names changed.