Digital BW, The Print

----- Original Message -----
From: "Austin Franklin" <darkroom@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Monday, August 19, 2002 8:45 PM
Subject: RE: [Digital BW] Dmax and drivers was Getting perfect neutral
prints from Epson 7600/9600 etc


> > Austin,
> >
> > I haven't a clue about the theory here but I have demonstrated to myself
> > with the original Piezo and the new PiezoTone inks that the Epson driver
> > produces a 100% level black square about 0.1 density units darker than
the
> > Piezo driver. Antonis reported that IP4 pushed the same ink about
another
> > 0.03 units darker than the Epson. So for whatever reason, the driver
does
> > play a practical role in the level of Dmax that is actually achieved.
> >
> > Martin
>
> Hi Martin,
>
> I assume you used the same inks with different drivers, right?
>
> If that is true, then, IMO, the driver is done poorly.  Something is fishy
> here.  I'll try a Piezo "black" and an Epson black, Epson driver using
> simply the single ink Epson B&W output...as it'll simply give me black ink
> only.
>
> Another thing, were the test all printed at the same time, on the same
paper
> (same batch, and same image), with the same ink (meaning the EXACT same
> ink), and done multiple times, and measured after the same amount of time
> (preferably immediately)?  I know this sounds anal, but I have found SO
much
> variance in these damn inks...the same print, printed tomorrow, will have
a
> variance of .1 density units from the one I printed today!  I've also
> noticed that the inks in the bottles aren't always fully mixed.  Sorry,
this
> stuff bugs me...
>
Austin,

I simply created a square in PS and filled it with 100% black. I printed
with the Piezo driver on one end of the paper then turned the paper around
and printed the square again with the Epson driver on the other end. I let
the print out settle for 24 hours and then took measurements. So same
printer, same ink, and same paper. The difference is definitely greater than
the variability of my Spectrocam.

Martin