QTR-Quadtone RIP

I have been very busy the last couple of weeks learning some of the idiosyncracies of QTR 
that I think could possibly be of interest to many, because some of the things I learned 
were surprises to me.

I was attempting to get a maximum dmax using the UT14 inkset, but this may apply to 
other inksets as well.  The inkset I was using had a layout as follows:
ink 1 K = Eboni Black
ink 2 C = Cool PK
ink 3 M = Warm PK
ink 4 Y = GLOP
ink 5 LC = Dilute Cool PK
ink 6 LM = Dilute Warm PK

I was attempting to get the maximum black possible on a semi-glossy paper (ILFORD 
Galerie Gold Fibre Silk) using the PK inks, without using the Eboni Black which would 
require the use of GLOP, since Eboni doesn't adhere well to glossy type papers.

What surprised me after printing the inkseparation wedge at 100% was and taking many 
density readings was that I was getting a higher dmax readings with the DILUTE Cool and 
Warm PK inks rather that the expected UN-diluted Cool and Warm PK inks.  I took many 
readings and double checked and noticed that even though the dmax decreased after a 
certain point with higher ink loads, as they do with some papers, that the highest dmax 
readinsg was with the two diluted PK inks; the Diluted Warm PK was actually higher (a 
little over 2.33 at 95% inkload) than the Diluted Cool PK (at about 2.15 at 100% inkload).   
The Cool PK in the C position was actually a little higher than the diluted Cook PK in the 
LC position (at 2.19), but not enough to mess with as you will see with my final result.

So what I ended up doing was creating a Warm curve using only the Diluted Warm PK ink, 
in the LM slot at 95 % inkload.  With my "Cool" curve I ended up using the Diluted Warm PK 
ink in the LM position at 95% inkload for the darker blacks, and the Diluted Cool PK in the 
LC position at 100%, and at 76% of the Diluted Warm PK.  You don't even noticed the 
diluted warm PK at this dark a black, but you do notice them being blacker, which 
accomplishes our goal of a maximum dmax.

After Linearization my final result was textbook ideal linear densities with a dmax of 2.27 
on both my Cool and Warm Curves.

Some other things I discovered for myself was that I achieved a much better linearization 
by adjusting the HIGHLIGHT, SHADOW, AND GAMMA settings to get as close to linear as 
possible before linearization; using these settings with it's resultant print of the 21-step 
wedge for the linearization readings.

I hope my comments may help some of you get the best profiles possible with maximum 
dmax,

Randy

Randy,
   Thanks for sharing your experience and interesting observations. It
does seem odd that you get a higher density using the dilute PK inks,
but perhaps it is possible that laying down the same amount of pigment
in a larger volume of dilute ink gives a different reflectance than a
smaller volume of concentrated ink.

I would also note, though, that it may be quite difficult to measure
differences in reflective density greater than 2.  The difference
between 2 and 2.3 is the difference between 1% of the light striking
the print being reflected and 0.5% reflected.  This could be very
sensitive to the angle of reflectance and other factors. But, if you
can see it and you like the difference, then that is what matters!

David







--- In QuadtoneRIP@yahoogroups.com, "Randy Rancier"
<randy_rancier2004@...> wrote:
>
> I have been very busy the last couple of weeks learning some of the
idiosyncracies of QTR 
> that I think could possibly be of interest to many, because some of
the things I learned 
> were surprises to me.
> 
> 
> What surprised me after printing the inkseparation wedge at 100% was
and taking many 
> density readings was that I was getting a higher dmax readings with
the DILUTE Cool and 
> Warm PK inks rather that the expected UN-diluted Cool and Warm PK
inks.

--- In QuadtoneRIP@yahoogroups.com, "Randy Rancier"
<randy_rancier2004@...> wrote:
>
> I have been very busy the last couple of weeks learning some of the
idiosyncracies of QTR 
> that I think could possibly be of interest to many, because some of
the things I learned 
> were surprises to me.
> 
> I was attempting to get a maximum dmax using the UT14 inkset, but
this may apply to 
> other inksets as well.  The inkset I was using had a layout as follows:
> ink 1 K = Eboni Black
> ink 2 C = Cool PK
> ink 3 M = Warm PK
> ink 4 Y = GLOP
> ink 5 LC = Dilute Cool PK
> ink 6 LM = Dilute Warm PK
> 
> I was attempting to get the maximum black possible on a semi-glossy
paper (ILFORD 
> Galerie Gold Fibre Silk) using the PK inks, without using the Eboni
Black which would 
> require the use of GLOP, since Eboni doesn't adhere well to glossy
type papers.
> 
> What surprised me after printing the inkseparation wedge at 100% was
and taking many 
> density readings was that I was getting a higher dmax readings with
the DILUTE Cool and 
> Warm PK inks rather that the expected UN-diluted Cool and Warm PK
inks.  I took many 
> readings and double checked and noticed that even though the dmax
decreased after a 
> certain point with higher ink loads, as they do with some papers,
that the highest dmax 
> readinsg was with the two diluted PK inks; the Diluted Warm PK was
actually higher (a 
> little over 2.33 at 95% inkload) than the Diluted Cool PK (at about
2.15 at 100% inkload).   
> The Cool PK in the C position was actually a little higher than the
diluted Cook PK in the 
> LC position (at 2.19), but not enough to mess with as you will see
with my final result.
> 
> So what I ended up doing was creating a Warm curve using only the
Diluted Warm PK ink, 
> in the LM slot at 95 % inkload.  With my "Cool" curve I ended up
using the Diluted Warm PK 
> ink in the LM position at 95% inkload for the darker blacks, and the
Diluted Cool PK in the 
> LC position at 100%, and at 76% of the Diluted Warm PK.  You don't
even noticed the 
> diluted warm PK at this dark a black, but you do notice them being
blacker, which 
> accomplishes our goal of a maximum dmax.
> 
> After Linearization my final result was textbook ideal linear
densities with a dmax of 2.27 
> on both my Cool and Warm Curves.
> 
> Some other things I discovered for myself was that I achieved a much
better linearization 
> by adjusting the HIGHLIGHT, SHADOW, AND GAMMA settings to get as
close to linear as 
> possible before linearization; using these settings with it's
resultant print of the 21-step 
> wedge for the linearization readings.
> 
> I hope my comments may help some of you get the best profiles
possible with maximum 
> dmax,
> 
> Randy
>
Randy
First let me thank you for such a detail description to help
beginners, must be one of the best threads on the subject here..It
certainly guides some of us struggling through this maze of confusion.
In your path to success on the subject, 
1. Did you print the separation strip through the Epson driver?
2. If so what settings
3. Did you eventually print through QTR using your warm and cool profiles
4. Did you use the split tone function and mix warm and cool on QTR
5. How do you measure your DMax? is that using a spectro? 
6. If its not asking for too much, is there anyway you could post the
heading of one of your ink description files here as an example, this
may really help some of us struggling with all the variables.

When I made my first 21step test strip using the Epson driver and
measured with eye one I found that I could not obtain a linearized
curve as there was a kink in the curve viewed in Excel, therefore I
just corrected one reading in excel and processed the .txt file and it
did create the output file through QTR linearize data file. Is this
the correct approach or did you follow some other method? I tried the
51 random test strip which had far too many kinks and I gave up trying
to linearize. Sorry for the long tread but some light on the above
would really help.
Dileepa

Dileepa, I don't have the time now to answer your questions, but will in a couple of days; 
tomorrow I'm going to the Lexjet seminar here in Dallas.  So, maybe tomorrow evening or 
Thursday.  One quick answer, you don't use the the Epson driver to print any of the 
calibration steps.  All I can say right now is read all of the applicable documentation that 
comes with QTR... AND there is definitely some really good info posted here under the "Files" 
section in the "Docs" folder; probably the best step by step guide I found was the 
"QTR_PiezoTone_cal_haney_01.pdf"  in the Docs folder.  This one document made a lot of 
things clear to me.  Also, the 'QTR Users Guide, even though it is primarily for PC users, the 
concepts are there even for us Mac users.  Hang in there; once you work through it, it starts 
to make since, and there is light at the end of the tunnel.

I wish I had the time to write out a step by step detailed guide, but not in any of my 
immediate future.

Randy

--- In QuadtoneRIP@yahoogroups.com, "Randy Rancier"
<randy_rancier2004@...> wrote:
>
> Dileepa, I don't have the time now to answer your questions, but
will in a couple of days; 
> tomorrow I'm going to the Lexjet seminar here in Dallas.  So, maybe
tomorrow evening or 
> Thursday.  One quick answer, you don't use the the Epson driver to
print any of the 
> calibration steps.  All I can say right now is read all of the
applicable documentation that 
> comes with QTR... AND there is definitely some really good info
posted here under the "Files" 
> section in the "Docs" folder; probably the best step by step guide I
found was the 
> "QTR_PiezoTone_cal_haney_01.pdf"  in the Docs folder.  This one
document made a lot of 
> things clear to me.  Also, the 'QTR Users Guide, even though it is
primarily for PC users, the 
> concepts are there even for us Mac users.  Hang in there; once you
work through it, it starts 
> to make since, and there is light at the end of the tunnel.
> 
> I wish I had the time to write out a step by step detailed guide,
but not in any of my 
> immediate future.
> 
> Randy
>
Randy
Many thanks, I started on this process using as suggested above,
having some success. Thanks again
dileepa