QTR-Quadtone RIP

I am using 2880 and only 2880. Why use anything else :)
Mike

On 30 March 2010 06:36, tboleyyh <tyler@...> wrote:

>
>
> StudioPrint uses rather severe partitioning, and successfully linearizes 6
> and 7 inks. Of course it costs much much more. My only point is that lots of
> overlap is not necessary for this, it can be done, and the number of inks is
> not the problem.
> Also, many of us prefer not to lessen the number of grays, as we don't find
> 3 Ks adequate for our particular needs. If you do, kudos, but one of QTR's
> great benefits is it's flexibility as a monochrome driver for all kinds of
> demanding setups for a variety of needs.
> Mike, are you at 1440 or 1880? Variable dot in every, of many, grays
> (1440x720) can be very difficult, even only 3. In many of these setups it
> works because of heavy light ink limiting, which is likely primarily small
> dots...
> Tyler
>
>
> --- In QuadtoneRIP@yahoogroups.com <QuadtoneRIP%40yahoogroups.com>,
> "shileshjani" <shileshjani@...> wrote:
> >
> > Mike,
> >
> > I must say I have never ecountered posterization issues with customary
> inks that use K, LK, and LLK alone, or as backbone followed by LM, LC, and
> others for toning via use of "toner" or "copy curve from" in QTR ink setup.
> >
> > I think Cone type overlap may (perhaps) be required when using 4+ gray
> inks, which in my opinion is at best an overkill, and technical mas@#$%^tion
> at worst. I have not seen a print that was better simply because it had 6 or
> 7 shades of gray. Try to reduce the number of gray inks in your set up, and
> use standard QTR curves design tools. I am curious what your eyes will see.
> >
> > Shilesh
> >
> > Shilesh
> >
> > --- In QuadtoneRIP@yahoogroups.com <QuadtoneRIP%40yahoogroups.com>,
> Michael King <drmrking@> wrote:
> > >
> > > Roy,
> > >
> > > >>If you have posterization issues it's almost certainly due to other
> > > issues.
> > > More bits and more overlap are pretty much the very last things to be
> > > concerned about. Posterization is usually in the image or you have bad
> inks
> > >
> > > So all I can say is that I have a image that posterizes with QTR curves
> > > (limited overlap) but not Cone style overlapping curves. Same inks,
> same
> > > printer. Solved the problem by using using overlapping curves and
> > > linearizing with my own spreadsheet based linearization tool. This 7
> ink set
> > > up is using a mix of HP-PK and Eboni MK (18% & 100%). It may have been
> > > caused by some other effect that I removed by using overlapping curves,
> but
> > > there is no doubt that overlapping curves solved the problem, whatever
> is
> > > causing it.
> > >
> > > Mike
> > >
> > >
> > >
> > >
> > > On 29 March 2010 19:00, Roy Harrington <roy@> wrote:
> > >
> > > >
> > > >
> > > > On Mon, Mar 29, 2010 at 9:02 AM, Michael King <drmrking@<drmrking%
> 40gmail.com>>
> > > > wrote:
> > > > >>>Is there any benefit in re-creating custom curves for this new
> version?
> > > > I
> > > > > have just finished profiling two papers for QTR and wonder if they
> would
> > > > be
> > > > > a) compatible, b) have greater accuracy with this new version?
> > > > >
> > > > > As I read in Roy's answer to my earlier question - there has been
> no
> > > > change
> > > > > to profiling. Its still 8 bit based. BUT he is interpolating
> between the
> > > > 8
> > > > > bit values to generate intermediate values to support 16bit.
> > > >
> > > > There have always been 256 points in the QTR curves but the values at
> each
> > > > of the points have always been 16-bit. The 256 points are already way
> > > > overkill
> > > > compared to, for instance, color ICC profiles. ICC color management
> > > > typically
> > > > uses interpolation with just 25 points so QTR curves have 10 times
> that.
> > > > Interpolation is a perfectly good technique.
> > > >
> > > >
> > > > >
> > > > > To be honest paper coatings are barely consistent enough across the
> page
> > > > to
> > > > > let you profile at 7 bits (128 values) never mind more than 8 bits.
> So we
> > > > > would be able to gain nothing from Roy directly increasing the
> curve
> > > > > resolution beyond 8 bits.
> > > > >
> > > > > You might ask what's the benefit of 16 bit printing ? Well I expect
> the
> > > > main
> > > > > benefit is in helping smooth tonal areas avoid posterization, by
> creating
> > > > > more ink values in the tonal graduation.
> > > >
> > > > If you have posterization issues it's almost certainly due to other
> issues.
> > > > More bits and more overlap are pretty much the very last things to be
> > > > concerned about. Posterization is usually in the image or you have
> bad
> > > > inks.
> > > >
> > > > Roy
> > > >
> > > >
> > > > >
> > > > > I've been wrestling with this issue for the last few months and
> have been
> > > > > experimenting with Cone style overlapping curves and QTR less
> overlapping
> > > > > style. There is no doubt more overlap reduces the problem BUT also
> for
> > > > some
> > > > > papers overlapping curves reduces dmax. So as usual there is no
> free
> > > > lunch.
> > > > > I am excited about the potential of 16 bit printing to address this
> issue
> > > > -
> > > > > just got to Hackintosh my PC first :)
> > > > >
> > > > > Mike
> > > > >
> > > >
> > > >
> > > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
>
>  
>


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