Re: separations for gum printing
" No need to even mark which is which, and --yes-- the differences are also easily seen onscreen." Boy, isn't THAT the case. I used CMYK negs for many years before even trying RGB and I never even had to label them. Looking at a set of RGB negatives I still scratch my head wondering how they can contain all of that different color data and look so similar. On Thu, Nov 20, 2008 at 1:18 PM, Diana Bloomfield <dhbloomfield@bellsouth.net> wrote: > Hi Marek, > With my admittedly limited experience with tri-color gums, my times are also > fairly similar-- but I do think I also compensate with development time. I > did make a few CMYK prints, though (with the K printed as pt/pd), but those > digital transparencies generated from CMYK (as opposed to CMY) are vastly > different. No need to even mark which is which, and --yes-- the differences > are also easily seen onscreen. Since I didn't print the black as gum, only > as platinum, I didn't really get to appreciate what a CMYK would be like-- > all gum-printed. Never used RGB, though. > Diana > > On Nov 20, 2008, at 1:52 PM, Marek Matusz wrote: > > > All, > This recent discussion on tricolor gum printing sparked my interest. My > printing times are about the same with all colors, but perhaps I compensate > with development time, these two variables are related. But that is not what > I wanted to discuss. Mostly everybody agrees that B channel (in the RGB > color space) intended for yellow printing always requires a different curve > then RG channels. This is also my observation and practice. The B channel is > almost always much 'flatter" then oher channels and requires a more > pronounced curvature. Quite frequently I do not have enough definition in > the B channel to get enough contrast resulting in prints with overall yellow > cast. > Since CMYK space and separations are intended for printmaking, which is what > we do in gum I started making CMY separations with K set to zero. There is a > visual difference on how the pictures look on screen in these two color > spaces (anyone interested should try to toggle between spaces in Photosop) > and also how the Y separation looks compared to B channnel in RGB color > space. It also seems like the colors are less muddy. I have only done a few > pictures so far, but I want to see if anybody is doing different methods of > generating separations for tricolor gums. > Marek > > ________________________________ > Proud to be a PC? Show the world. Download the "I'm a PC" Messenger > themepack now. Download now. >
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