What working color space have you decided to use from here on out? I ask because the author of the aforementioned Cameratico.com article recommends using QTR-Lab working color space (I'm not talking printer profile, but rather working space PS>Edit>Color Settings). If your answer is QTR-Lab, then I must ask you this. Does the QTR printing GUI (module, pipeline, driver, thingamajig, whatever you call it) bypass the Epson ABW printer driver (like PrintImage and QImage RIPs do) and print with a 1.0 gamma response curve? If no, then what does the QTR printing GUI actually do that the printer ABW driver does not do? My experience with QTR was limited to building an ICC profile and nothing more--I've never printed directly from QTR itself.
According to my previous post it doesn't matter what working color space the patch set was generated in PS when printed via PS, Epson Driver in ABW mode and "Printer manages color" (assuming it has been natively generated in PS). So, now I started my tests with untagged 51 random patch set I have generated with Argyll.
QTR printing is another story (I am not talking about using QTR "*.exe" scripts to generate icc). Since, QTR assumes linear gamma (=1.0),
I convert my grayscale photo to QTR Gray lab .icc (linear L*) in the PS, save as LZW tif and open and print via QTR Gui.
Important thing is, as Frep has written, QTR has nothing in common with Epson driver and ABW. Prior to make your print, you have to prepare in QTR appropriate curve(s) for you print mode (resolution etc) and paper used. Spectro is needed, but you gain control on each color channel in the printer and proportion of how ink is mixed to make given shade of gray. That is not an easy task, and QTR has no clear documentation, but the result is really worth trying.
Many years ago I needed to create specialized charts with superimposed sine functions of differing frequencies for studying system MTF. Linearity was important. [...] I used standard color mode w color management disabled but it should apply to Adv. B&W just as well. Anyone tried something like that?
In retrospect I think that approach could be improved by grouping 4 pixels (at 720PPI on Epson) and adjusting them to improve the smoothness of each RGB step.
Doug, I have no problem with using Matlab, I used to be an expert in that excellent tool in the past - but would you be so kind to explain what do you mean in reference to simple patch generation? Especially, the issue of smoothness?
@unesco: #1 surprises me a little, because depending on how you printed these various test charts, I'd have expected some differences, but perhaps you printed them in a way to prevent this. #2 is what I would have expected. #3 is an interesting observation that I hadn't noticed before.
#1 new image created in the PS in given color space, patches generated in my PS by posterising gradients, printed in ABW and "Printer manages color" mode
#3 visually the difference between 2880 and 1440 dpi is slight, however in 1440 mode a* vs b* curve for L* going from 100 to 0 is more straight from the white point of the paper to the black point. In 2880 it is more curvy in midgray-to-shade area. The difference is at a level of dE=~1