QTR-Quadtone RIP

Before burning through more ink and paper testing your custom curve, maybe try one of the `canned' Eboni-6 curves by Paul Roark and see what you get. You should be seeing a gradual darkening from 70% through 100%, whereas your initial post suggested you're not. 

That said, if you're getting 100% black at the 90% patch, your default (K) ink limit or black boost might be too high. The ink limit on your next highest density ink after K (I believe it's C) also might be too high. 

Also, I'd recommend first reading through the QTR user guide and Paul Roark's PDF on Eboni-6 (Paul's Web site in general has a wealth of information). I'd also suggest examining closely Paul's  Eboni-6 profiles, looking at how he constructed them -  the densities, and ink limits, and how one ink blends into the next. He also wrote a PDF on Eboni-4-Plus that has a nice section on building QTR profiles. 

Mark 


--- In QuadtoneRIP@yahoogroups.com, "supracode" <seanu@...> wrote:
>
> Thanks Mark...
> 
> I'll try doing the measurements in Lab instead of density. As far as improving the pre-linearization... Should I increase the point where the darker inks kick in... ie if full black is measuring at %90 change it to 95% and so on down the line for each ink? It sounds like I'll be burning through a lot of ink and paper.
> 
> 
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "mccarvill" <mccarvill@> wrote:
> >
> > 
> > 
> > Hi Sean,
> > 
> > Others with more experience will probably chime in but, in the meantime, I'll suggest:
> > 
> > 1)measure Lab L instead of density
> > 
> > 2)try to achieve a fairly linear curve before you linearize. The linearization checker spreadsheet available here is a useful tool - http://www.piezography.com/PiezoPress/blog/piezography-k7-inks-and-curves/checking-your-linearization/
> > 
> > 3)once you've achieved a fairly linear curve, measure Lab L once again and input that data into the curve's linearization 
> > 
> > Mark
>