QTR-Quadtone RIP

Yes, I have just started using QTR on a Epson 2200 with Jon Cone's NK7  
inks. I am very pleased with the results also. I have made profiles for  
Red River Polar Matte and Red River Dourian Art papers and I am getting  
nice smooth results with both papers. You can really tell the difference  
in tonal qualities between the two papers. The Polar Matte is very neutral  
to cool toned and the Dourian Art is warmer toned.

My questions are for Roy or Jon or anybody else who is familiar with the  
profile creation process in QTR. When you produce the first calibration  
print using the ink separation test page, you use it to set the initial  
ink limit. At this point should you set the limit to the max value from  
any of the ink channels or should it be derived from only the blackest ink  
channel? In my case the black channel maxed out at around 40% but the  
magenta channel went up to 90%. I wasn't sure what to use.

It wasn't clear in the user's manual that the even though you reference  
each channel to the next darker ink, the values that you put into the ink  
setup page need to be referenced to black. Each percentage figure needs to  
be multiplied by the previous value so that as the inks get progressively  
lighter, the number get progressively smaller. With seven inks, I had to  
round off and ended up with values of 3, 2, and 1 for the three lightest  
inks. Am I doing this correctly? It was the only way I could get the curve  
creation tool to put the inks in the correct order and make a smooth curve.

I ended up with Gray Curve values of 10 for Highlight and Shadow and 6 for  
the gamma setting. Do these values sound about right? The final 21 step  
print was very good and although I did the linearizion using my scanner to  
get the input values, there was not much change in the final print.

The only remaining problem is with the blackest step on the RR Polar Matte  
paper. The black ink amount seems to have reflections that actually lower  
the DMAX when looking at the paper from certain angles. Do I just need to  
lower the ink limit for that channel?

This is all new to me and I am sure with some more experience I will be  
able to figure out the relationships between all these variables. As I  
said I am getting very pleasing results so far, I just want to make sure I  
am on the right track.

Thanks,
Steve Taylor



On Wed, 25 Oct 2006 08:17:30 -0700, ser_gio_s <ser_gio_s@...> wrote:

> extremely happy... PC user... been testing all weekend with Epson
> matte... results way above any expectation... is anybody using QTR
> using  with piezography or similar?
> regards
> Sergio
>
>
>
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