QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "Jeff Randall" <jrandall@...> wrote:
>
> There are several profiles written for the 2100 and the UT3D 
> inkset.  They are installed when you set up QTR.  If you are on a PC, 
> just select Quad21-UT3D as your printing model (upper right drop down 
> in the QTRgui window) and the available profiles will be accessable 
in 
> the curve set up drop down area.  

Jef,

I checked but I can't find this printing model myself in QTR. I 
installed the previous version 6 months ago and just updated to 2.5. 
You're sure they come with the installation?

Marco,

I have the same setup. There is not comprehensive guide for this set 
(yet). This an area that is still moving pretty fast and not everything 
is laid down in formal documents. This is how I dealt with it.

1) read the Tom Moore's user manual (comes with QTR, also available on 
the QTR website). Although not perfect it is a pretty good intro into 
QTR & curve creation.

2) realize you will need four curves for each paper: warm, cool, 
selenium and neutral.

3) start with the warm curve, using's Tom's procecure. Start of or 
compare with curves for similar paper/ink sets. Since the UT3D warm 
inks are identical to those of the UT7 inks they are a good starting 
point. I have uploaded a few early UT3D curves (derived from the UT7 
ones) in the file section. Note that these are 1440 dpi curves, while 
I'm moving to 2880 dpi (better Dmax and smoothness).

4) create a cool curve, as a modification of the warm curves. The cool 
LK and LLK have (nearly) identical densities, so that's a fairly easy.

5) experiment with the QTR blend sliders to mix the cool and warm 
curves to obtain a (near) neutral setting.

6) use the mix obtained in 5) to create a neutral curve by setting the 
ink limits of the cool and warm LK and LLK inks in the same ratio as 
the ratio above. This should give a decent starting point, but refine 
this one furhter to your taste/need.

7) create a selenium curve with for the LK the neutral mix obtained 
above and for the LLK use the selenium ink. So the selenium toner is 
used as just another LLK ink. 

Some remarks:

There are many refinements possible to the above. For instance, I'm 
still working on the selenium curve since I don't exclude that one 
could get some selenium tone in the shadows. But as a starting point it 
worked for me.

Although most standard curves are 1440 dpi ones, there seems to be a 
growing consensus that 2880 dpi is the better setting in this case, 
taking a slower printing speed for granted. In 2880 dpi one does not 
need the underprint the black eboni with LK as sometimes is advocated.

Success!

Joost