QTR-Quadtone RIP

I have a nice job that involves reproducing a large series of 17th
century European Maps. I have done several nice variants of monochrome
using QTR that I like and am trying to sell the client on. However,
the original maps, although in excellent for steel engravings over 300
years old have yellowed quite a bit in the highlights. The engraved
lines are a reddish sepia.

In my many tests I have found no setting with QTR curves that allows
me to introduce this yellowish tone into the highlights and simulate
the paper yellowing of the originals. I have gotten very good
reproduction using RGB workflow but I would like to do these out of
qtr if possible. 

My understanding is that the QTR Ultrachome driver shuts off the
yellow for the purposes of greater longevity. But I am not 100% sure
of this.
Does anyone know?

John

In other words, I'm not trying to do a dual color output but would
rather have a little more yellow in the singe color used. When I push
toward sepia or try variants on warm or sepia I always end up going
more toward red. This sepia workflow does not have yellow content from
what I can find.

john

John,

A quick way would be to edit one of the sepia profiles to remove the  
LM (just set the LM limit to 0 in the descriptor file) save this  
profile as "yellow" and then use the profile blender to blend this  
"yellow" profile with a warm profile (just the carbon inks) to get  
the level of yellow tone you want.

Carl

On Apr 21, 2006, at 12:41 PM, john dean wrote:

> In other words, I'm not trying to do a dual color output but would
> rather have a little more yellow in the singe color used. When I push
> toward sepia or try variants on warm or sepia I always end up going
> more toward red. This sepia workflow does not have yellow content from
> what I can find.
>
> john
>

Thanks Carl,

I'll try that this weekend. 

I just made a great match to the original deteriorated document by
using rgb colorspace and the Epson driver and creating a hue sat/curve
combination. That way I was able to control the reddish sepia
engraving with the yellowish stained/sepia paper ground. 

But for other yellowish sepia situations what you described is what
Roy also just wrote me and I'm sure that would work well.


Thanks,

John




--- In QuadtoneRIP@yahoogroups.com, Carl Schofield <scho@...> wrote:

>
> John,
> 
> A quick way would be to edit one of the sepia profiles to remove the  
> LM (just set the LM limit to 0 in the descriptor file) save this  
> profile as "yellow" and then use the profile blender to blend this  
> "yellow" profile with a warm profile (just the carbon inks) to get  
> the level of yellow tone you want.
> 
> Carl
> 
> 
> On Apr 21, 2006, at 12:41 PM, john dean wrote:
> 
> > In other words, I'm not trying to do a dual color output but would
> > rather have a little more yellow in the singe color used. When I push
> > toward sepia or try variants on warm or sepia I always end up going
> > more toward red. This sepia workflow does not have yellow content from
> > what I can find.
> >
> > john
> >
>