[alt-photo] Re: Sizing

[Peter Friedrichsen]

Re Staining pigments

I have found that the  pigment additives must have a significant 
effect on staining. The surfactants and dispersants that are added to 
reduce agglomeration of the particles in the tubes, also help to wet 
the surface of the paper which "sucks the particles deeper in where 
they stay. When I switched to grinding my own powder pigments into 
the gum, my staining problems were much reduced even for the same 
pigments namely quinacridone red, phthalo blue (both green and red 
shift)  and various nickel azos.

I have frequently printed on Fabriano Artisitco hot pressed with its 
own built-in AKD sizing. I have found however that tones are smoother 
when I apply my emulsions to gelatine size. I always get a slight 
mottling of tones on the Fabriano. This can be good or bad, but I 
think it is worth mentioning al least if only to emphasize that 
sizing type and/or amount may affect more than just the degree of staining.

Peter Friedrichsen