Digital BW, The Print

If you are using the K7-2880-(papername) curves that are part of the download package of QuadTone RIP - those are made with the Piezography profiler. In 2005 when we changed from PiezographyBW ICC to Piezography K7, we changed the gamma of the "profile" or the "curve" from Gamma 1.8 of the ICC version to a Gamma of 2.2 for the QTR version.

So we do print with a Gamma of 2.2 and your display should be calibrated to Gamma 2.2 - even if you use the D50 standard - option in a 2.2 Gamma instead of 1.8.

For legacy files you either start over or simply convert them from whatever your working space was (in your case Dot Gain 20%) to Gamma 2.2 using Perceptual.

Because the old version 2000 - 2002 PiezographyBW did not follow and congruent gamma or contrast curve from printer model to printer model, there were some whacked out Printing Ink Setups that were saved as the working space. Those you would not probably want to convert. Those were only suitable as Preview working spaces.

For Windows you do not have a Previewing space in any regard for QTR because it operates stand alone. But if you image in Photoshop you will want to work in a Gamma of 2.2 as your working space - hence converting to it...

From Mac - one prints directly out of Photoshop.

regards,

Jon Cone
Piezography


--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "ausdlk" <ausdlk@...> wrote:
>
> In reading some of the Piezography K7 documentation, I read that files should be in Gamma 2.2 profile and that I should change the Photoshop grayscale color space to Gamma 2.2.
> 
> That's all well and good.
> 
> However, I have numerous grayscsle files with an embedded Dot Gain 20% profile.
> 
> The Piezography docs says "as a rule, you should never convert a grayscale image from one profile or gamma to another in order to keep the smoothest tonal transitions possible".
> 
> This seems like a Catch 22. 
> 
> Don't a need to convert my files from Dot Gain 20% to Gamma 2.2 before printing?
> 
> And, if so, should I select "Perpetual" or "Relative Colormetic"?
>