QTR-Quadtone RIP

I would just go with K7 matte inks for matte and glossy and spray the glossy
prints.
That what I do, its simple and effective. I get great blacks on glossy L* 4
and below.
I profile the sprayed targets to get soft proof profiles and also to use
convert to ICC when it suits the image.

Mike

2009/8/1 robert49brake <robert49brake@...>

>
>
> --- In QuadtoneRIP@yahoogroups.com <QuadtoneRIP%40yahoogroups.com>,
> Michael King <drmrking@...> wrote:
> >
> > Of course I should have said how you get from L* 0 - 10 in your on screen
> > image ...
> > Robert shadows are low L* values. I am not 100% sure what you mean by
> "matte
> > papers in the deep shadows (90-100)"
> > What does the 90-100 refer to ?
> >
> > Mike
> >
> > 2009/8/1 Michael King <drmrking@...>
> >
> > > Robert,
> > >
> > > Here are the L* readings I measured some time ago with HPR+K7 on the
> R1900
> > > for RGB 0 - 27
> > > It turned out it wasn't a particularily good batch of HPR I chose to
> > > measure with 256 steps.
> > > often I can get down to L* 16.x
> > >
> > > RGB, L* 0 17.75519 3 18.5508 6 19.38313 9 20.26813 12 21.233 15
> > > 22.31181 18 23.18398 21 23.84067 24 24.91842 27 25.61255
> > >
> > > So as you can see K7 puts out good seperation between low RBG values.
> In
> > > fact its pretty much linear across RGB 0 - 255 range. How you get from
> L* 90
> > > - 100 in your on screen image to something on your printer that shows
> > > seperation in those values is a workflow/profiling issue not a K7
> issue.
>
> Thanks, Mike. I should have been more specific (end of a long day:) I was
> refering to the 90-100 steps of a 100 step grayscale. I can see from your
> readouts that the Piezography profiles/inksets are getting something I
> cannot duplicate with QTR and a custom inkset I'm playing with. The inkset
> is Eboni Matte Black and 6 dilutions of HP Vivera Black plus glop. The
> obvious goal is a dedicated b&w 8 head printer with matte and glossy
> capabilities. (I've been patiently waiting for J. Cone to do all the work:)
> Piezography seems to be going in another direction so I decided to play with
> it myself.
>
> The hang up on this and a previous UT-3D inkset with the 1800 has been
> separation in the deepest shadows and artifacts at the transition to the MK
> ink. When looking at Cone's .quad files he obviously has a different method
> of profiling (creating the curve files) for QTR. One obvious aspect is that
> he is able to overlay his individual ink curves in a way that QTR, in it's
> native partitioning, does not. Everything in QTR seems to be contained in
> the .quad file instructions to the printer, but, how you get there seems a
> matter of choice.
>
> I'm happy to note that you are using a 1900. I think it's close enough to
> an 1800 to eliminate the printer as the source of the artifacts, or at least
> there IS a method of profiling that printer that can eliminate them.
>
> Robert
>
>  
>


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