Re: two questions about gum
I'll chime in with my two cents here with Marek. Curves should be taking care of all things--either a too dark print or a too flat print. If not, the curve is wrong. And, if the printer's adjustments are not turned OFF, then the printer will also alter the curve that one makes. That's why the PDN system does not use the printer driver; it's like you go to all this work to make a curve and then send it to the printer and the driver mucks it up on the fly--usually it comes out a paler version of the negative which would in turn print too dark.
I don't know what your printer is, but in my Epson 2400 I have to select ICM and then "no color adjustment". In the 4000 and other printers there are TWO places you have to select "no color adjustment"--but that's on a Mac driver and Macs have to be told things twice because they are dumber (heheheheheh).
But, as Ron Reeder pointed out at APIS, to each his own--three systems of curve making, download Dan Burkholder's curves who has done all the work in the trenches for you, use the Reeder method which utilizes the printer driver, or use PDN system which turns it off and makes the curves WYSIWYG. That is a crass over simplification of diginegs but maybe makes the point I am trying to say. (But, Dan, do you have curves for gum?)
But one more point, Charles--or was it Loris--magenta/red is a really strong pigment, unless it is PR209 which is sometimes called quinacridone red or q coral or whatnot--it is a fairly weak red albeit beautiful corally red really nice for some images. But in general, magenta and thalo are strong colors and need to be cut down in the first place BEFORE curves are made to make sure you won't go too dark when the layered colors are finally done. For instance, I may use the 1/4 the magenta that I do raw sienna, or even less. It's that different. I figure out my mixes of each color that I am going to use before hand and then always use that and develop my curves and times for those mixes. So I standardize first, get that practice correct, and then I can be loosey goosey about it, cut my pigments to real low saturation, etc. However, I can't say I have ever used time to vary a print because, as Mark reminded us, you're not gonna get your highlights printed in, and why would you want to print a layer of just shadows when your print is too dark in the first place? Unless it is your highlights that are too dark, too, I suppose, might be the scenario.
All of this said, there are gum printers who adjust their process to plain old uncurved negatives for the last century and a half and have beautiful work, so to each his own--there are many ways to skin this cat. When I started teaching gum this last semester, I first taught them with uncurved all ink negs and even tho the shadows were blocked up, they produced some pretty amazing first gum prints. These higher tech ways are only necessary if the original practice is not working well. There is a pretty major difference between my gum prints before and after curves when laid side by side, but if not seen side by side I don't think the buying public would say my pre-curve prints are nasty.
----- Original Message ----- From: "Marek Matusz" <firstname.lastname@example.org>
Sent: Wednesday, September 26, 2007 7:18 AM
Subject: RE: two questions about gum