QTR-Quadtone RIP

Hi Tom,

It's not clear to me either...

I'm figuring out a workflow to make digital negs. As these have inverted characteristics 
from a print, the dot gain works differently; it separates dark tones and compresses light 
tones in the print - so maybe the normal QTR curve-generating algorithms are not ideal. 
Maybe they are fine, if I tweak them with the tools provided, but by figuring it out from 
scratch I end up with a better idea of what underlies the program.

I'm working with a 2200 and my first try was with K7 inks. They seem to be too fragile on 
transparent media, so my next move will be K3 ink in refillable cartridges, using light 
black, light-light black, maybe a dash of yellow mixed into them, and maybe diluted for 
some ink positions.

Prints from digital negs tend to be grainy in the light tones, and the theory is that this is 
caused by gaps between the ink dots on the neg. and/or differential UV blocking by 
different color inks in colorized negatives. It seems from what I read that it helps to lay 
down several inks at once, using lots of nozzles, and have the inks be all the same color. 
Hence QTR and an Excel sheet to compile the ink profile. The worksheet can give me a 
graphical representation of the optical density and ink volume of the profile, if the dot 
gains can be figured in. Easy for individual inks, but tricky to figure how inks of different 
dilution interact.  

Maybe I'll actually print something one day...

Best,

Ben

--- In QuadtoneRIP@yahoogroups.com, "Tom Moore" <r.t.moore@...> wrote:
>
> 
> 
> > -----Original Message-----
> > From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> > Behalf Of stolptse
> > Sent: Monday, February 12, 2007 9:28 AM
> > To: QuadtoneRIP@yahoogroups.com
> > Subject: [QuadtoneRIP] Re: How do I import Excel files into QTR?
> > 
> 
> [...]
> It's not clear to me what you're doing, but it seems to me that you are
> trying to do manually what the Curve Creation algorithms in QTR do
> automatically. What is the benefit of creating a curve using Excel?
> 
> > 
> > Has anyone worked on a way to figure out the dot gain of combinations of
> > inks at different
> > dilutions? The calibration routine makes it easy for the individual inks,
> > but I'm wondering
> > what happens in combo - the possible number of combinations is high, so a
> > rule of thumb
> > would take some of the guesswork out of designing a profile.
> > 
> > 
> [...]
>