Re: my pigment dilutions
See a new scan: http://www.loris.medici.name/gum/2Y_1M_1C_diluted.jpg I have put few drops of water over half of the black patch and brushed over this. The result is a warm gray. The rectangle on the left reads R157 G149 B128, the one on the right reads R218 G214 B200. From this, can we draw the conclusion that I have to use less concentrated yellow? (About 1/3 less, keeping the concentration of M and C constant.) Regards, Loris. 26 Ekim 2008, Pazar, 12:50 am tarihinde, Loris Medici yazmış: > Katharine, see below: > > 25 Ekim 2008, Cumartesi, 10:15 pm tarihinde, Katharine Thayer yazmış: >>>> Dear All, >>>> At this URL I posted a visual of my pigment dilutions: >>>> >>>> http://christinaanderson.visualserver.com/Text_page.cfm?pID=2076 >>>> >>> >>> Thanks for that, that's helpful. Will analyze more deeply (by >>> comparing >>> our yellows) but at first sight it seems that both of the my planned >>> magenta and pthalo concentrations are considerably stronger (in >>> proportion >>> to yellow) than yours. >> >> >> I think this may have more to do with pigment choice than >> concentrations, Loris. The PY 151 is a very light pigment; to my >> mind it simply can't hold its own with most magentas and cyans and >> for that reason I don't recommend it for tricolor but prefer yellows >> with a little more oomph to them. > > I've just made a test (albeit a clumsy one): > > I mixed 2.5 to 3 part PY151 + 1 part PV19 Rose + 1 part PB15:3 over a > sheet of Yupo. I didn't measure exactly, just eyeballing the squeezed out > paint amnts. Hence the designation "clumsy", and the uncertain proportion > of Yellow. > > See the result below: > > http://www.loris.medici.name/gum/2.5-3Y_1M_1C.jpg > > The black section above is a fully exposed and developed glossy RC print > that I use as reference black in scanning (log 2.0 or slightly more print > density). Below this, you can see a patch made by mixing paints. I > averaged inside the white square and the color sampler says it's R17 G15 > B13 (L2 a1 b1 in Lab mode) relative to Dmax of a glossy RC S/G print. From > this I understand Y > M > C; Yellow is pulling both Green and Red Up, and > since Blue is less than Green that means Cyan is weaker than Magenta (if > not, then Blue would be stronger than Green). Correct me if I'm wrong > please - because all this color stuff is still new to me. Anyway, this is > quite convincing black (both in terms of density and neutrality), would > you agree? In the light of this, can we say PY151 can hold its own with > PV19 Rose and PB15:3, or should I test it using a different method? > > Thanks, > Loris. > > >
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