Digital BW, The Print

Shelish's experiment confirms Tyler Boley's statement that "The Epson 
RGB driver does not allow any CMY under 100%K."

IMO, Jon's web page comparison between Piezo and Epson/Woolf was more 
marketing than science.  What he appears to be trying to show is that 
Piezo uses less black and therefore the PiezoTone black should fade 
less if using Piezo driver rather than the Epson driver where black 
ink is turned on much earlier (simple math -- less fade-prone ink 
less fade).  

The posted step-wedge printed without black ink using Epson/Woolf 
appears to show inking in the 100% patch.  Maybe Jon did not clear 
the black head of residual ink (as Shelish did).  Jon also made 
statements about where various densities of ink were layed down using 
the Epson/Woolf workflow that I could not independantly confirm based 
on the posted images.  

Jeff Randall



--- In DigitalBlackandWhiteThePrint@y..., "Paul Roark" 
<paul.roark@v...> wrote:
> Shilesh,
> 
> I'm glad someone finally did the "clear base in the black cart"
> experiment -- which I've been "going to do someday" for a long 
time.  Thanks
> for the post.
> 
> >...
> >I loaded MIS clear base in the black ink position.  The color
> >cartridge was Epson OEM dyes.  I printed 1-inch square pure 
black, ...
> >1280, ... gamma 2.2, PhotoShop 5.5.  PCM unchecked, using three 
media
> >different settings....
> 
> >... After the previous black ink was
> >sufficiently purged, the 1-inch pure black squares printed white 
(!)...
> 
> This is what I think is the ideal situation.  To get the deepest 
black, the
> paper ought to be loaded with as much ink as it can hold, and all 
that ink
> should be black ink.  Otherwise, the black ink is being diluted 
with lower
> density ink.
> 
> >... So, clearly the post by Cone is not the full story.
> 
> I don't understand how he could let a post out that would undercut 
his
> credibility more.  I hope that the settings or whatever produced 
the results
> in his post are explained.
> 
> >The Epson driver did not appear to use yellow ink in the
> >100% square; in all of the media settings I tried
> >(PQIJ, MPHW, and IJBL Film).
> >...
> 
> >When I used Piezography in these experiments, I more-or-less
> >duplicated what was posted by Cone.
> 
> That must mean the driver is incapable of pumping out enough black 
ink to
> get the paper up to what it can hold -- or the thing is just purely 
written.
> That result might explain why the Piezo driver produces a weak black
> compared to the Epson driver -- at least on the printers I use 
(1160 &
> 3000).
> 
> >... I doubt the fade seen in PT-K ink
> >has much to do with the so-called "workflows".
> 
> A good RIP can restrict the black to the darker tones more than the 
Epson
> driver can.  However, this is a 2 edged sword.  The fading/warming 
PT-K
> problem will be more hidden in some images, but the RIP image may 
also be
> more susceptible to a posterization in the deep shadow tones.
> 
> Paul
> http://www.PaulRoark.com