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QTR-Quadtone RIP

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grayscale linearization using PS curves

grayscale linearization using PS curves

2005-10-24 by digital_joshua

Hello chaps,

I'm entering the dance of linearization process and catch almost all 
the subtilities involved in the game of creating a new curve..

*deleting shadow, highlights and linearization data
*ink limit (60% in my case)
*black correspondance of light black at ink limit (22,5%)
*Print of the 21 scale wedge
*Scan the patch with a fladbed scanner and work it with PS in lab 
mode
*Creating the "pre linearization" PS curve is almost OK, but it led 
to somme limitations explained below:

The paper (Arches watercolor infinity) has a creamy white which 
correspond to 7% black. The darkest patches level up to 85% black 
for the theoretical 90-95-100%. The linearization process works 
well, but only between 10 and 85%

Do you have any piece of info on how to get back these cutted parts 
of the histogram? 

Thanks for yous answers,

Digital_joshua

Best canned 2200-UC curves for Inkjetart.com sample pack

2005-10-24 by Alan Eckert

I recently ordered a coated fine art photo paper variety pack from 
Inkjetart.com, which I'd like to try on my Epson 2200 with Ultrachrome 
inkset.  It includes HPR, Illuminata, Somerset Velvet & Textured, and 
Arches Infinity Smooth & Textured.  My standard of comparison is 
Entrada Bright White, for which Roy has not supplied curves, but his 
Entrada natural curves seem to work OK.

Bearing in mind that I don't have a spectrophotometer & thus can't 
generate my own curves, which canned curves will work the best on these 
other papers I'd like to try?

Incidentally, I did search the earlier posts and found a URL for HPR 
curves, but these were not printing curves, but rather soft-proofing 
curves, so as far as I can tell they won't help.

Thanks!

Alan

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