Digital BW, The Print

Alan,

I take what the President of Lyson said with a big grain of salt.  Lyson is
predominantly a dye ink company. I read the article as a sales pitch for
Lyson inks.

For example, consider his attempt to suggest that dye printers should not be
used with pigments.  People have been using Epson dye printers with pigments
for years.  The pigment particle sizes are about 0.1 micron, whereas the
nozzle size is about 25 microns.  The size of the particles is not a
problem.

The 7500 (pigment printer) and 7000 (dye printer) are said to be
mechanically exactly the same.

All printers will get clogged if ink dries on the head, and it does appear
to be true that pigments are marginally more troublesome than dyes.  This
is, no doubt, why the main difference I can see between the Epson dye and
pigment printers is the amount of automatic cleaning cycles they do.  So,
check your nozzles and run a cleaning cycle if needed.  Taking control of
this yourself probably saves a lot of ink compared to the printer
automatically doing cleaning cycles whether they are needed or not. 

On another subject -- the need to match the ink and paper to get best
keeping -- his conclusions apply almost exclusively to dye inks, not
pigments.  With dyes we know that the swellable and mordant (Kodak)
technology papers give dyes much better lightfastness -- many times better.
They do this by pulling the dyes into the paper and protecting them better
from oxidation.  

With pigments the particles lay on top of the paper and are not greatly
affected by the paper.  My fade testing shows some differences between
papers, but I'm not sure I've ever seen more that about a 20% difference.  

The main concern with the substrate for pigments is that the image forming
substance is so good it will outlive the substrate.  Wilhelm rates the "B&W"
UltraChrome pigments on EEM as having a display life (> 150 years) that is
longer than the dark storage life of EEM even under ideal conditions (110
years).

If one wants images to last, I'd still bet on carbon on cotton.  I think
there is plenty of test data to back this up.  

Sure, a "properly toned and processed" silver print may be more lightfast,
but even here the toning most of us (and Ansel Adams) were doing has been
found to be defiant.  As for dark storage, I'd still bet on carbon on
cotton.  Wet process prints have no buffering, and without that the air will
start an acidic cascade.  Inkjet printers can use buffered substrates and
avoid this risk. 

Paul
www.PaulRoark.com 

For UT2 information, curves, and settings see:
http://home1.gte.net/res09aij/
____________________________________




-----Original Message-----
From: Alan Zinn [mailto:AZinn@...] 
Sent: Saturday, February 28, 2004 12:33 PM
To: DigitalBlackandWhiteThePrint@yahoogroups.com
Subject: [Digital BW] Re: Dye-Based or Pigment-Based?

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Roger Smith 
<rbsmith252@c...> wrote:
> I thought the group should be aware of the great article in Photo 
Techniques
> this month by Tony Martin(President Lyson USA).  He discusses Dye-
Based or
> Pigment-Based inks and debunks some of the myths concerning digital 
inks.
> This article does a great job explaining general ink theory and 
what we can
> expect or not expect from various product designs. Not only would I
> recommend that each person on the list should pick up a copy of the 
current
> (March/April 2004) Photo Techniques and read this article, but you 
may want
> to subscribe.  This publication is one of the very best, full of 
useful
> information with each issue.  I really look forward to it every 
other month.
> Unlike some of their competitor publications they have embraced the 
switch
> to digital with full vigor and use as much space on it as they do 
darkroom
> techniques.  Not bad for a publication that at one time was entirely
> concerned with darkroom technique.  If a person is going to 
subscribe to any
> photo publication today this and LensWork (for their wonderful B&W
> portfolios and interviews) should be on the top of their list!  A 
wealth of
> information and enjoyment.  I have no connection to these magazines 
other
> than I subscribe to both. I hope someone finds this suggestion 
useful.
> Thanks.
> 
> 
> Roger Smith
> E. Lansing, MI 48823--


Roger,

I looked over the Martin article and learned a few things. I have 
some questions though. He says that dye printers should be used with 
dye inks and pigment printers with pigment inks. That leaves the 
choices pretty slim doesn't it? And many of us have been using all 
the Epson printers for pigment inks after some struggle. What Epson 
printers are exclusively for pigment ink? 

From what he says about keeping properties I concluded that there are 
too many variables to have decent data. In other words "pigment inks 
on rag paper" should mean nothing to a buyer as far as 
archivability.  That's no doubt why we seldom see anything but silver 
prints in galleries. 

AZ
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