Digital BW, The Print

"mcrib13" <edmondkim13@...> wrote:

>... I just set up my Epson Workforce 1100 and EB4 inks 
> but I've run into some problems.
> 
> I've tested some of the profiles Paul made with my cheap epson presentation matte paper ...


I've never tested or profiled that paper, but I've added a curve and ICC for Ultra Premium Presentation Matte ("UPPM") paper that might be close.

Go to http://www.paulroark.com/BW-Info/MIS-WF1100-Profiles.zip to download the new curve and profile.  

UPPM took a lower ink limit than the other papers.  I'm guessing the UPPM profile &/or curve will work better.

 
> ... I applied the curve to the PS raw file. Then I also applied the same curve to the step wedge.

To make your own ICC profiles, you will need to print the appropriate curve on both a 21-step test file (in Adobe RGB (1998)) as well as the QTR test file, saved as a raw file.

> How does an RGB curve work with a grayscale file?

Badly. That is the main problem you're having.

You need to convert the 21-step to an Adobe RGB file, then apply the curve.  Then when you print the 21-step, be sure the profile in the print preview is also Adobe RGB.  In older systems you can also use "no color management" in the preview.  CS5 will not allow that, however.


> I wasn't sure what profile ... same as my working space ...

The concept is correct.  But, use Adobe RGB (1998) for the 21-step when you make a profile.  

(For printing through a final ICC, you'll leave the files grayscale, and the ICC will do the converting to Adobe RGB.)


> I used my spyder3print sr to take the linearization measurements.

That is the unit I use and prefer.

 
> I dropped the raw file and the exported txt file onto the qtr-icc-rgb file and it created the icc.


Drop the 21-step Lab file and the qtr-icc-rgb image file (with *.acv curve on it and saved as a *.raw file) into QTR's Create ICC-RGB.  By the way, I usually re-name the qtr-icc-rgb file to the same as the text file -- aside from extension -- so that I don't mix up these files or save over the original qtr file.


> It also gave me a warning in the text file that a soft proof could not be created because the rgb curves (raw file I'm assuming) werent in ascending order.

To be compatible with soft proofing, one of the R, G, B curves must go from 255 to 0 with at least some minimal positive slope throughout the range.  This usually is not the case with partitioned RGB curves. 

> The last thing I tried was printing the step wedge with no curve applied using the gray gamma 2.2 as the printer profile. The printed wedge though not linear, did not have any dip in the gradation. I then took the measurements with the spyder. ...(no raw file used). The resulting profile gave me a nice linear step-wedge. The problem is that the middle grays look more coarse like it's using more of the K inks.

What you did there is make a non-partitioned profile.  Your main problem, above, was not converting the 21-step file to RGB before putting the curve on it.

There is likely another problem that you may not have noticed.  The dmax is probably reached too early -- before 100% input.  UPPM appears to hit the dmax at 91%.  The new partitioning curve in the Zip file, above, corrects this.

I hope this helps.

By the way, I'll be making more profiles for the 1100 Eboni-4 system.  I now have it installed in my 1100 and think it's an important platform to support.  Being able to the most lightfast B&W prints for the least amount of money seems like a significant niche for the B&W market -- and it's what I like.

Paul
www.PaulRoark.com