QTR-Quadtone RIP

Shilesh Jani wrote:


>As you know I 
> use QTR for my b/w printing. I create the hue purely visually, 
> without aid of an instrument. 

Probably another thread but I have been thinking about this
for a long time:

The toners in quad ink sets and in K3 ink sets are measured on
density in the Quadtone linearisation step. Would it be
possible to measure them in Chroma in all QTR applications
where it counts and so make the hue creation a bit more
controlled ? Right now I tweak the toner curve to get an
acceptable hue over the range, after that I have to linearise
again, which will influence the toner curve again etc. There's
no real solution to get the last 90-100% black in line on hue
without density loss or dotgain increase but I can live with
that. But getting it correct from paper color and over the
main part of the ramp would be nice. Just Chroma may not be 
enough as the mix shifts in hue from paper to the shadows as 
well. I know another step would require a color engine of some 
kind in the program. Probably too much to ask for.

I think David Tobie recognises this flaw in most quadtone 
solutions and adds solutions to PrintFIX Pro but they are only 
usable in an RGB CM environment.

Ernst


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           Ernst Dinkla


www.pigment-print.com
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