QTR-Quadtone RIP

I am currently developing a tool that allows me to directly read data 
from my PrintFixPro. This could perhaps lead to a tool that make 
linearization of Inks much easier than now. But I still have to learn a 
lot about side effects and technical limitations.

Here's what I have done so far:

I have measured five of eight inks from the calibarion sheet for the 
R2400 and created a graph for the density readings of 5 Inks from the 
UT3D Set. I have left out the last three Inks (Y,LC,C) to save some 
time. For a complete solution I will have to include them later.

Here's a png with the graph of the five Inks:

http://www.michael-ring.org/UT3D.png

Now I am asking myself how to make sense out of the data in order to 
linearize the inks.

Denisity of the blank paper is 0,09.

LLK ink is nearly linear to 100%, ending at a density of 0,74.
LK is linear to 100%, not as good as LLK, but quite O.K. It ends at 1,7
K is only usable up to 25%, where it reaches 1,55 (??)
LM  is nearly linear to 100%, ending at a density of 1
M is approx. linear till 45%, Density 1,86. Max Density of M is 2,25 
reached at 75%

There are two aproaches from now that I can see:

Print the Sheet again at 75%, this should give me Dmax of 2,25 for M
Then I could find the takeover Points from LM to M and from LLK to LK to K

I would end up with two linearized Inksets:
one neutral Inkset consisting of LLK,LK (and K??) with Dmax of 1,7
one cool toned Inkset consisting of LM and M with DMax of 2,25

However, I am unable to use the 25% of the Light Inks because I have 
linmited Ink to 75%

Is this also possible:

I leave the Ink limit at 100%;
Set Takeover Point for LLK and LM to 100%
Limit M to 75% and K to 25%

Can QuadtoneRIP handle this? Am I missing something/doing something 
wrong or am I an the right track with my thoughts?

If yes then I will try to automate the process.

The question that still puzzles me is what to do with the K-Ink. Should 
I leave it out or is it better to  use it too in order to have more Inks 
active at the same time?

Thanks in advance,

Michael

Michael, 

I wonder why are you doing this work? The program that comes with 
PrintFixPro (version 2.0, of course) seems to be able to do miracles, 
at least if you read what C.D. Tobie posts around here.

Regarding QTR, you don't need to linearize each ink separately. You 
describe how inks will be loaded along the density axis, then 
generate QTR profile for this layout, then print the test ramp -- 
with all relevant inks involved, then measure it and add corrections 
into QTR. After that your printer is more or less linear in QTR for 
this profile. You could use different subsets of inks for different 
profiles, linearize them, and then use QTR to mix those subset in one 
print. All this process is documented in the manual.

--Sergei


--- In QuadtoneRIP@yahoogroups.com, Michael Ring <michael-ring@...> 
wrote:
>
> I am currently developing a tool that allows me to directly read 
data 
> from my PrintFixPro. This could perhaps lead to a tool that make 
> linearization of Inks much easier than now. But I still have to 
learn a 
> lot about side effects and technical limitations.
> 
> Here's what I have done so far:
> 
> I have measured five of eight inks from the calibarion sheet for 
the 
> R2400 and created a graph for the density readings of 5 Inks from 
the 
> UT3D Set. I have left out the last three Inks (Y,LC,C) to save some 
> time. For a complete solution I will have to include them later.
> 
> Here's a png with the graph of the five Inks:
> 
> http://www.michael-ring.org/UT3D.png
> 
> Now I am asking myself how to make sense out of the data in order 
to 
> linearize the inks.
> 
> Denisity of the blank paper is 0,09.
> 
> LLK ink is nearly linear to 100%, ending at a density of 0,74.
> LK is linear to 100%, not as good as LLK, but quite O.K. It ends at 
1,7
> K is only usable up to 25%, where it reaches 1,55 (??)
> LM  is nearly linear to 100%, ending at a density of 1
> M is approx. linear till 45%, Density 1,86. Max Density of M is 
2,25 
> reached at 75%
> 
> There are two aproaches from now that I can see:
> 
> Print the Sheet again at 75%, this should give me Dmax of 2,25 for M
> Then I could find the takeover Points from LM to M and from LLK to 
LK to K
> 
> I would end up with two linearized Inksets:
> one neutral Inkset consisting of LLK,LK (and K??) with Dmax of 1,7
> one cool toned Inkset consisting of LM and M with DMax of 2,25
> 
> However, I am unable to use the 25% of the Light Inks because I 
have 
> linmited Ink to 75%
> 
> Is this also possible:
> 
> I leave the Ink limit at 100%;
> Set Takeover Point for LLK and LM to 100%
> Limit M to 75% and K to 25%
> 
> Can QuadtoneRIP handle this? Am I missing something/doing something 
> wrong or am I an the right track with my thoughts?
> 
> If yes then I will try to automate the process.
> 
> The question that still puzzles me is what to do with the K-Ink. 
Should 
> I leave it out or is it better to  use it too in order to have more 
Inks 

> active at the same time?
> 
> Thanks in advance,
> 
> Michael
>