QTR-Quadtone RIP

Roy did not write the tutorial "Making a B&W ICC with a Scanner". It was written by Paul 
Roark:

http://home1.gte.net/res09aij/Making_B-W_ICCs.htm

I'm not sure this will help but I noticed the Gray values have "%" sign and Paul recomends 
this format: 95.00 not "95% ". So I don't know if the ICC profile is written properly with the 
"%" sign. Here Roy could answer if % sign will confuse the ICC building script.

> I wasted time and material with no  success.

Welcome to the club! You are not wasting time and material...you are learning how this all 
works.

Best,

John



--- In QuadtoneRIP@yahoogroups.com, "dgattarino" <dgattarino@...> wrote:
>
> Dear Roy,
> I have followed carefully your instructions in the "Making a B&W ICC
> with a Scanner" writeup.
> Here is my workflow:
> 
> 1) Open in PS CS2 the 21-step.tiff file. Reply "do not assign any
> profile" to the request of colour management
> 
> 2) Print with preview on EEM with Epon R2400 using:
>       a) Let printer determine colors
>       b) intent perceptual
> In the printer property dialog:
>       c) ABW with default settings
> 
> 3) Scan the print with a HP Scanjet 4870 adjusted in order to get the
> 0%, 50% and 100% patch according to your writeup.
> 
> here are the mesurements done with PS:
> Gray   Lab_L
> 0%     96
> 5%     96
> 10%    94
> 15%    88
> 20%    83
> 25%    77
> 30%    71
> 35%    65
> 40%    59
> 45%    53
> 50%    47
> 55%    43
> 60%    39
> 65%    36
> 70%    31
> 75%    27
> 80%    23
> 85%    20
> 90%    17
> 95%    16
> 100%   16
> Kodak Gray Card   42
> 
> 4) I used the above measurements to create curve  QTRgui and ICC
> profiles in QTR_Create_profile.exe.
> 
> 5) In both cases, the profiles produced provided very poor results
> (softproofs and prints dont quite match).
> 
> I have done many tests using both QTRgui adn PS with the profiles I
> created. I wasted time and material with no  success.
> 
> I came to the conclusion that the scanner is not properly calibrated.
> Infact, adjusting the canner settings to match only 3 patches (as you
> suggest) may be insufficient, unless the scanner is very linear (wich
> is not, just by looking at the abve table of measurements.
> 
> Would you be so kind, please, to give more measurements of other
> patches of the 21.step.tiff file so I could calibrate my scanner
> a little better?
> 
> Thank you very much 
> Sincerely
>   Daniela
>