QTR-Quadtone RIP

I am new to this group, having found QTR only about 2 weeks ago.

My system uses Win XP, and an Epson 2100 printer using the MIS inks (with Continuous Ink System) and using the Universal black ink (rather than wanting to change between the Eboni or Photo blacks if I change paper with a large waste of ink flushing the system).  Hence I am working out how to generate my own profiles or curves for this combination.  

I have the Colorvision PrintFixPro Spectrocolorimeter to use, and found the paper by Tom Moore an excellent starting point, 

Previously when printing out step wedges I found the black end of the printout always rather dark, and a preliminary run through with QTR showed dramatic improvement.  Having now been through the system roughly to get a grasp on how it operates I want to repeat it more thoroughly to improve the result.

When I print the Ink Separation test page and check the densities of the black I find, plotting the result, the curve has 2 straight sections intersecting just under 50% black.  There is little increase in density above this point. (1.91 at 45%, 1.96 at 50%, 2.02 at 55%, and from 60-100% increasing only from 2.04 to 2.12.)  

It is easy to measure the LK ink max density as equivalent to 24% of the Black.

Am I correct in saying the Default Ink Limit for my 2100/2200 printer with MIS Universal Black ink is maxing out at 50% level, rather than the 80-90% level suggested on P13?

I am also puzzled by the UC-Neutralizer option given in some of the sample files, especially as I can find no reference to it in the paper, or in any of the other papers I have found.  Having listed all the parameters in the QIDF files I see that this term sometimes occurs and the terms COPY_CURVE_LC=LK and COPY_CURVE_LM=LK are omitted.  

I have used a table listing all parameters in the QIDF files for the various UC ink/paper options supplied with the program to help me understand the way to vary between the warm result of the Epson inks, especially the LK, and the addition of LM and LC to give a Cold tone, and then mixing for a proper neutral black.  

Thanks to the authors for what appears to be an excellent program, I had no hesitation in sending my $50 contribution, and will be recommending it to a number of friends in Camera clubs and other groups.  Suspect I will be asked to talk on it when I get more experience, it is wonderful to see someone's eyes light up when you mention being able to get neutral balck prints, and control warmth and the degree of cool.

Jim

[Non-text portions of this message have been removed]

Jim

You don't say it explicitly, but I infer you are using MIS colour inks, not
the Quad inks. 

> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of Jim Thyer
> Sent: Saturday, September 01, 2007 9:33 AM
> To: QuadtoneRIP
> Subject: [QuadtoneRIP] Ilford Smooth Gloss-MIS ink
> 

...

> When I print the Ink Separation test page and check the densities of the
> black I find, plotting the result, the curve has 2 straight sections
> intersecting just under 50% black.  There is little increase in density
> above this point. (1.91 at 45%, 1.96 at 50%, 2.02 at 55%, and from 60-100%
> increasing only from 2.04 to 2.12.)
> 
> It is easy to measure the LK ink max density as equivalent to 24% of the
> Black.
> 
> Am I correct in saying the Default Ink Limit for my 2100/2200 printer with
> MIS Universal Black ink is maxing out at 50% level, rather than the 80-90%
> level suggested on P13?
> 
A dmax of 1.96 (or even 2.12) seems low for a glossy paper. Perhaps that is
the nature of the Universal K you are using. In any event, I would try using
55% as the default ink limit and then try squeezing out a little more dmax
using Black Boost.

> I am also puzzled by the UC-Neutralizer option given in some of the sample
> files, especially as I can find no reference to it in the paper, or in any
> of the other papers I have found.  Having listed all the parameters in the
> QIDF files I see that this term sometimes occurs and the terms
> COPY_CURVE_LC=LK and COPY_CURVE_LM=LK are omitted.

The UC_Neutralizer is an artifact found in older curves. Ir has been
superseded by Copu_Curve_from, which is more general.

> 
> I have used a table listing all parameters in the QIDF files for the

...

> 
> Jim

...