Re: Gum and Photogravure, was: varnishes
16 Kasım 2008, Pazar, 10:11 pm tarihinde, Loris Medici yazmış: > Perhaps, but in that case what is the fact that makes gum prints as stable > as carbon prints (you said that earlier in this thread) whereas they > differ so much in binder? (One gelatin, the other gum arabic.) Apologies, it seems that I just missed this: "...I'm comfortable saying that carbon prints and gum prints (both using permanent pigments of course) shoud be similar in permanence, because the process by which they are made is similar, and the end product is crosslinked colloid holding pigment in both cases. It's possible that crosslinked gelatin and crosslinked gum arabic are different in some way that affects permanence, but as far as I know, there are no data touching on that question, and until that information is available, I'm comfortable saying that there's no logical reason, or evidence-based reason, for saying that carbon is more permanent than gum (or vice versa, for that matter)..." So, we can't say "carbon is as stable as gum or gum is as stable as carbon" too, since there isn't any evidence proving that also. In this case, the only thing that we can say about this issue is "I don't know"... Regards, Loris.
|