Digital BW, The Print

Yes, Diana, I have seen the exact same problem in 100% black 
areas when printing with OPM (v 1.02). I think it's turning out to be 
a fairly common defect--you're the 4th or 5th (including myself) 
that I know about--among the relatively few people who have 
reported _any_ feedback about OPM in forums and newsgroups. 
Antonis and Carl (and some others I guess) state that they do 
not see this problem, so it's a little confusing as to why there is 
such a disparity in the results. The version I have of OPM is 
whatever was available from the Bowhaus website as of one 
week ago. If there's anything more recent I don't know how to get 
it.


Aside from that "show-stopper" of a problem, the results I got 
were quite nice. I used Carl Schofield's linearized versions of 
Antonis's profiles. I can reproduce the defect in the 100% black 
test patch of Antonis's 26-step grayscale, but it is not apparent in 
any of the lower densities.

My temporary "workaround" for dealing with the 100% black 
issue is to simply reduce 100% black pixels to 99%. This is 
easily done in Photoshop by making a one-level change in the 
"output levels". Of course that also adds one level to all the tone 
values below 128, but the effect may not be very noticeable. And 
then all the 99% black areas print OK.  Probably there is a better 
way to do this with PS curves. I hope Bowhaus comes 
up with a fix because their approach to B&W printing seems so 
promising.

Phil




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Diana 
Park <dip@m...> wrote:
> Antonis or anyone,
> 
> Has anyone had a sudden problem printing solid black areas 
with OPM 
> 1.02 on a Mac? Yesterday I did a print with large solid black 
areas 
> and it printed fine. The next print had weird white gaps running 
in 
> the printhead direction (almost like the heads were dragging 
against 
> the paper). Did a nozzle check - fine. Cleaned the print heads, 
just 
> in case - fine. Printed the file from Photoshop - fine. But print 
the 
> file from OPM and the gaps/streaks appear. But only in the 
100% black 
> area. I haven't changed the black cartridge recently - maybe I 
should 
> try that. I also tried reinstalling the software, and I've tried 
> different profiles, but still the streaks. Any ideas??
> 
> Diana
> (who's TRYING to make some Jerry Olson memorial prints, but 
not succeeding...)