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

RE: archivalness of gum

<< I believe many of them are originally pigments of dyes. >>

I meant "pigments or dyes."


> -----Original Message-----
> From: Dave S [mailto:fotodave@dsoemarko.us] 
> Sent: Saturday, December 22, 2007 12:14 AM
> To: alt-photo-process-l@usask.ca
> Subject: RE: archivalness of gum
> << I think gamboge, lakes, etc. are also names of tones, not 
> pigments, tho some pigments could be so named, I suppose... >>
> I believe many of them are originally pigments of dyes. Like 
> gamboge is a plant. I have use true gamboge in painting. It 
> is in a form of a stick (they take the liquid (sap?) from the 
> plant and put in in a thin bamboo trunk and after it dries, 
> they break the trunk to get the gamboge out). You "grind" it 
> like you grind an ink stone, but it is not actually grinding, 
> it is more like dissolving. Gamboge is not permanent, so 
> today it is replaced by more permanent synthetic version, so 
> gamboge becomes a tone name.
> Lakes are all plant dyes and so are very fugitive too. 
> Today's lake are indeed hue/tone names made from synthetic mixes.
> Same with indigo which originally was made from indigo plant. 
> It has a beautiful purple tone, but it is also fugitive. 
> Today's indigo is a mixture of prussian blue and quinacridone 
> red. Those who are used to true indigo sometimes complain 
> that the synthetic indigo is too colorful (the true indigo is 
> more muted), but this can be fixed easily by adding just a 
> touch of black; so today's indigo is also a hue name.
> Dave