QTR-Quadtone RIP

Andrew Maier <andrew@...> wrote:

> **
>
>
> I am trying to profile my Epson R265 (R260 in the US) using a 21 grey wedge
> and a SpyderPrint 3 spectrometer. I have installed the Ultratone 3D inks
> (using the matte black ink).
>

Note that the UT-3D inkset generally uses Eboni in the K position, but the
M position is a neutralized PK for glossy paper.

See http://www.paulroark.com/BW-Info/UT-3D_Readme.pdf for a description of
the inkset.  Profiles are available for downloading.  Although I don't have
one for Ilford Galerie Gold Silk, take a look at the curves for similar
papers.  Starting with one of those curves would make sense.

So far I have created profiles for a few matte
> papers (Hahenmühle Photo Rag, Ilford Heavyweight Matt Paper and Ilford
> Galerie Smooth Fine Art Paper) with some success.
>

The trick for glossy papers is to turn off the Eboni and use the M-position
ink to generate the 100% black.



>
> I now would like to profile the the Ilford Galerie Gold Silk (a baryta
> paper, which I rather like), but when doing so I get LAB values which are
> inverted at the black end (See results as the bottom)....
>
I suspect you are not turning off the Eboni.  The driver injects Eboni MK
as the 3 color curves approach the black point.  You stop that by having
one of the inks head back down, ultimately to 0 at the 100% black input
point.  See the curves I've made for the inkset and glossy papers.  (Let me
know if there is a problem with the pre-zip file method I used for
downloading.)

If you are turning the Eboni off, then the other options are that the ink
load may be too high for that paper.  Which paper type is specified in the
driver alters the ink limit, and you can also lower the black ink load by
having the Green curve (Magenta ink control) stop at 90%.  That is, when
the input is 100%, have the Green curve only at 90%.  Be sure the blue
(and/or red) curve(s) are totaly "off" by that point.  You don't want the
driver to put any Eboni MK into the mix.

Hope this helps.

Paul
www.PaulRoark.com


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