QTR-Quadtone RIP

Thanks again Paul for your reply.

Yes M&C are the same density, LM and LC are very close to each other.
K is MK not PK. The paper is Epson Archival Matte.

"Keep in mind that, in the QTR partitioning, the inks in a progression must be different densities."
The progression is the grey step wedge? which would mean that I can't use both M & C in the printer, as they are the same density.

I used a profile .qidf from the 1290 set UT2 Enhanced matte Carbon (I think) parsed the text and then renamed, filled in the values etc.

I will try the setting that you have suggested and see what it looks like. 

Cheers
Greg


--- In QuadtoneRIP@yahoogroups.com, Paul Roark <roark.paul@...> wrote:
>
> Greg <gregnixon@...> wrote:
> 
> > **
> >
> >
> > I am attempting to create a profile with my 1400 using UTFS inks.
> >
> My memory of this setup is that the M and C are the same density, and the LC
> and LM may be the same or very close.  "Keep in mind that, in the QTR
> partitioning, the inks in a progression must be different densities."  So,
> you'll have to have the grays be, for example, Y, LC, C, K, and then set up
> a toner channel with, for example, Y, LM, M, K (I'm forgetting if the K
> needs to be there).
> 
> Is this matte paper with K = Eboni?
> 
> At any rate, first try Y, LC, C and K.  have the others not used.
> 
> If you are using PK and have it in the K position, recall that the C and M
> might have a dmax that is greater than the PK, but they'll do that with huge
> loads that will probably result in pizza wheel marks.  So part of what you
> need to do is reduce the ink loads of the lighter inks below their dmax
> points.
> 
> >
> > Looking at a printed 21 step wedge, the lighter end seems to rise smoothly
> > to about 60% where it flattens out, and from there on there is not much
> > difference between the darker steps.
> >
> 
> What profile where you using?  Was this the pre-linarized QTR output from an
> initial profile?
> 
> As long as the differences in the 21-step print are enough that the results
> will linearize with QTR, this might not matter.  You're often better off
> with compression of the dark end than not because this gives the program
> real data to use as opposed to interpolation.
> 
> >
> > The prints look as you would expect, not too bad until the part-shadow and
> > shadow.
> >
> > I have an idea that the dark grey ink is being set as lighter than it
> > really is.
> > When I print the first calibration print, the K ink limit comes up at 45%
> >
> 
> If the K is fairly flat between 35 and 45, consider putting the ink limit at
> 35 and the boost to 45.
> 
> Consider using 35 as the ink limit for the M and C -- in fact for all inks.
>  Use less light ink.  It's expensive water and the 1400's 1.5 pl drops don't
> need it.  Particularly with glossy papers & inks, the higher the load, and
> wetter the paper, the more problems with pizza wheel marks.
> 
> ... in the calibration scan, the 100% patch of the K row is the same density
> > right down to 45%.
> >
> That is rather normal.  You want to set the final K ink load at the left
> edge of the plateau.  But, again, I prefer to use boost for the final 10%
> because that area usually has a very low slope.
> 
> That means that I am attempting to find the 100% LK point down below 45% of
> > K. I think it is actually higher than that.
> >
> There is no LK in that inkset.  But, again, see what the density of the
> lighter inks are at 35% and consider that as the default ink limit.
> 
> Later when the toner channel is set up, split the ink limit between the gray
> and toner channels.
> 
> I hope this helps.
> 
> Paul
> www.PaulRoark.com
> 
> 
> 
> 
> >
> > Any comments?
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>