QTR-Quadtone RIP

>If this now famous 1 pt image file would be made available 
>we could make our own opinion. 

I've used resolution test files for some time that I simply make in
Photoshop.  I believe the top resolution of the Epson driver is 720 ppi, so
that is what the file is.  It can be downloaded at
http://www.paulroark.com/BW-Info/Resolution-chart-720ppi.jpg
(There does not appear to be any difference between this Jpeg and the Tiff
original.)  The file is 1" x 0.3".

I've added a "one point" text sample to this.  There are 72 points per inch
in the current U.S. method, according to Wikipedia
(http://en.wikipedia.org/wiki/Point_(typography))  So one point text is 10
pixels high in a 720 ppi file.  This includes the top of the tallest capital
letter and the lowest tail, in addition to a 1 pixel top margin.  This is
really small.  I used the PS text function to make 10 point text in a file
that was 7200 ppi and then resized to 720 ppi.  I made one of the text
sections with no anti-aliasing, and one with "crisp" anti-aliasing.  Given
the few pixels involved, neither is particularly good even on the monitor. 

Evaluating the printed images is tough if one does not have a very good
scanner.  Seeing the details is a bit beyond the limits of my 1600 dpi Epson
flatbed, but after sharpening 125% PS, one can start to evaluate the
relative quality of the printing.  
See http://www.paulroark.com/BW-Info/Resolution-comparison.jpg 

I've included a screen grab of the Piezo test in the above image.

A drum scanner is really needed for this task.  On the other hand, with a
good loupe, one can see more than my scanner, and the text is actually
readable -- with some effort.

The bottom line I saw was that with the 2200 and 1400, with Carbon-7 and
Eboni-6, respectively, and using the Epson driver and QTR, the one point
type is reasonably clear with all of the above combinations.  There is no
significant difference between the Epson driver and QTR.  The 1400 is a bit
sharper than the 2200, but in normal viewing, one would not see any
difference.  The Piezo printing from the test on the web appears to be in
the same league with what I see with the Epson driver or QTR and the inksets
I use.  

I do not have a K3 ABW setup to test.  It would be interesting to see a good
scan of a print of the above test chart with K3 ABW.

Paul
www.PaulRoark.com