Digital BW, The Print

<homershannon@...> wrote:

> **
>
>
> I'm trying to put together a routine for good quality, neutral glossy
> prints using the UT14 ink set. ... The paper I am using is Red River Arctic
> Polar Gloss.
>


> I've read Paul Roark's document http://www.paulroark.com/BW-Info/UT14.pdfand think I have it understood. For the purposes of testing the image I am
> working with is Keith Cooper's black and white test print.
>
Does that test image have a 21-step test file in it?  Reading a 21-step
file with a spectro or scanner will produce the best final image usually.
 I have several posted, including one at
http://www.paulroark.com/BW-Info/21-step.jpg that can be saved as a Tiff
file (recommended).


> This is my image manipulation process:
>
> Open the test image in CS4. Change the Image Mode to RGB Color. Apply the
> curve UT14-Gloss-N-4.acv. I then print the image.
>
> Printing the image with printer controls, ultra premium presentation matte
> paper and gamma 2.2 yields a pretty good print that is very neutral in
> coloration. However, the D-max of black is low and the mid-range is a bit
> too light.
>
The C and M inks in UT14 are a neutralized PK and PK, respectively.  The
curve you've mentioned, like all that were written for the UT14 inkset
assume that Eboni is in the K position.  For glossy paper, the curves
generate the 100% black from a blend of the  C (PKn ink, Red curve) and M
(PK, Green curve).  To reach the load required for a good dmax, you need to
print with "No Color Adjustment" in the Epson driver.  See page 7 of
http://www.paulroark.com/BW-Info/UT14.pdf .  Color Controls imposes a lower
ink limit on the non-black inks.  No Color Adjustment assumes some other
profile takes care of that task and gives you a higher ink load, which is
needed for a good dmax.

To find the best dmax, you can print with a curve that is nothing but two
straight light curves for the C (Red) and M (Green) curves from 0 to 100,
with the Y (blue) curve flat from 0 - 100 so that no Y-position ink is used
at any point.  The 21-step test print produced will sometimes hit its dmax
at something like 95.  You can use that as the end points of the curve
you're using.  That is, go into the curve and move the black end points of
the existing curve to the point you've now identified.

Alternatively, to find the best dmax you can print with a curves set that
has C (red curve) at 100 from 0 - 100, M (green curve) a diagonal line from
0 - 100 (end points (0, 0) and (100, 100), and Y (blue curve) flat (no ink
used).  The dmax might well be hit before the M (green curve) hits 100.
 This is actually what was done for the existing curve you are looking at.

The surface is very glossy with no non-reflective areas.
>

Good.  If glop can be avoided I would do so.  Some of these modern papers
have such a nice surface that the less that is on them the better.

I created an .icc using QTR. I adjusted a 21-step scale image with the same
> .acv as with the test image, then printed it and scanned it. Using this and
> the master 21-step scale image, I generated an .icc. The print with the new
> .icc is quite different than the print with the printer controls, but not
> better. Here are the issues:
> D-max is no better than with the image using printer controls.
>
You must use "No Color Adjustment," not "Color Controls."  Photoshop needs
to control the color management, not the printer.

 Good luck with the process.

Paul
www.PaulRoark.com


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