QTR-Quadtone RIP

Tom

You're finding out what I learned - making curves for the UT7 inkset is a
little more complicated than the UC, but not that difficult once you've done
one.

Generally, (or at least so far) I don't use the toner curves with UT7 and
matte paper. For a cool curve for Matte the L, M and LM inks used as grey
inks. For a warm curve (again for matte paper only) the K C and LC are used
as grey inks. A neutral image is achieved by blending a warm and cool curve
when printing.

For glossy and semi gloss papers such as Epson Premium Semi Gloss, the K ink
is not used. In this case, for a cool curve for example, the M and LM are
used as the black inks and a little bit of C is used in the deep shadows to
achieve the best possible dmax. Look at the Ilford Smooth Pearl curve as an
example.

Basically, with QTR any ink position can be considered to be a grey ink. The
"K" ink is that grey ink with the greatest density - it is assigned 100%
black and the density of the others are defined with respect to that ink.

See more comments below.

HTH

Tom Moore


> -----Original Message-----
> From: QuadtoneRIP@yahoogroups.com [mailto:QuadtoneRIP@yahoogroups.com] On
> Behalf Of Tom Husband
> Sent: Sunday, October 09, 2005 8:18 PM
> To: QuadtoneRIP@yahoogroups.com
> Subject: [QuadtoneRIP] Creating Curves UT7 and 2200
> 
> I'm creating some curves for UT7 and a 2200 printer.  I just
> characterized the inks and will calibrate ink density.  Looking at the
> ink pattern page it's hard to tell which are the gray inks.  The .qidf
> file for EEnhMatte-cool uses black, magenta and light magenta.  Does
> that mean it uses only black and then M and LM for cooling it down?

K M and LM are "considered" grey inks for the purposes of this curve.

> Do I figure densities for M against K and LM against M?  It looks like

Yes, eventually all lighter grey inks are stated with respect to K

> the existing curve did that.  Which positions are black?  It looks
> like K, C, LC and LK.

With QTR any position can be black. For an EEM cool curve, the K M and LM
inks are grey inks. Generally, the LK is not used when making curve
(although I have made a Black only curve using only K and LK). I think the
LK ink is only there to fill a slot and for those who wish to print without
curves using UT7 inks.

  Is that right?  If I wanted to create a neutral
> curve I would figure densities for these four inks right?

Not for matte papers. For those you make a cool curve using K M and LM inks
and a worm curve using K, M and LM inks and then achieve neutral by blending
a cool and a warm curve. I don't know of any curve sets for a matte paper
that have a neutral curve. There are some for RC papers.

It was a
> lot easier when I was using the UC inks with just two blacks.
> 

Easier, maybe; better, hopefully not.

> Thanks,
> 
> Tom
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