RE: Gum Calibration 3 (Dark Tricolor)
Thanks much Marek. Especially about roller coating. That seems to use quite a lot of paint -> will definitely resort if I can't manage to coat as evenly as I'd like it to be... For now I'll continue with brush coating -> thinner! I'm just doing a test by diluting the stock pain/gum solution. I'll see if that's too little paint (probably it'll turn up as you say). You're right about brush and sprayer but I want some consistency right now (and less stress). Regards, Loris. 27 Ekim 2008, Pazartesi, 5:39 pm tarihinde, Marek Matusz yazmış: > > Loris, > By all means experiment. It is the best way to learn gum. > Just looking at you note and remembering previous posts I have a few > comments. > > It seems to me that diluting your stock pigment solutions with additional > gum will lead you to weakly pigmented layers. I can only judge that basis > my use of Daniel SMith pigments, but somehow I do not suspect that other > brand contain 2x the amount of pigment. Your statement that individual > layer are too dark and hence the need to add more gum leads me to the > conclusion that you coating is too thick. That would also agree with your > difficulty of smooting the layers out. It is just about impossible to > smooth thick layers of gum. > > I would suggest dilute your stock solution with dichromate 1 part stock + > 1 part dichromate and skip the additional gum. Measure the amount of the > mix that you use to arrive at consistent layer thickness. > FOr coating pour the mix on paper, quickly brush it in making sure it is > spread all over the print and start rolling with the foam roller (I roll > in one direction up and down and them side to side). Keep rolling applying > less pressure as you go. You will end up with a very smooth coat (my > practice is about 1 minute). If you keep rolling too long the mix gets too > tacky you will start see roller marks. > The roller has to be damp, but not too wet. Try coating 5-6 sheets at a > time. By the time you are done with the first sheet the roller will have > the correct dampness to it and would have picked some paint for a steady > state work. By the time you get to the 6 or 8th sheets you will have the > feel for the coating. > If the roller becomes too wet (long rolling times) just roll it over dry > paper towel. > Remember that the most creative tools for gum are the brush and sprayer > bottle during development. They might help you more then overly compicated > negative systems.
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