Digital BW, The Print

Thanks for your advice.  However, all our published testing is done by
independent third parties to internationally agreed standards.  If we
think the "... King is naked", we will say so, irrespective of group
sensibilities.

We use hard scientific data and then seek independent corroboration from
respected independent organisations.

As a matter of record, we use The Printing Industries Research
Association International (PIRAi) and Leeds University Department of
Colour Chemistry.  Incidentally, both organisations use the Blue Wool
Scale test together with Delta-E readings; as does The Society of Dyers
and Colourists.

I think it is disingenuous to suggest Image Alchemy is somewhat
eccentric in preferring to use scientifically sound research, carried
out by reputable and independent research organisations.

I do have a problem with Wilhelm Imaging Research (WIR) stating that so
and so ink will last X number of years before fading.  We know that
Lyson's Fotonic ink was accredited by WIR as having a life of 70 years
and yet in an independent test carried out by Leeds University's
Department of Colour Chemistry, the magenta and light magenta inks
failed to get past BWS 2!

My contention is that many organisations use WIR to give them a level of
credibility that they often don't deserve.

Paul Banks
Image Alchemy Ltd
--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Steve Kale
<stevekale@...> wrote:
>
> Failed Thespian
>
> I really would encourage you to have some side by side testing done
should
> you wish your new ink set to gain some serious traction.  It generally
> doesn’t pay to fight the market, especially one as feisty as
this one.  This
> path has been well-trodden and very recently.
>
> Regards
>
> Steve
>
>
>
> From: Paul Roark paul.roark@...
> Reply-To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Date: Fri, 02 Mar 2007 21:02:14 -0800
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: RE: [Digital BW] Re: New graduated black inks -Blue wool
ratings
>
>
>
>
>
>
> > Our inks are tested to an internationally accepted standard
> > the Blue Wool Scale (BWS).
>
> I just want to comment a bit on the Blue Wool standard.  It has been
used by
> many industries for quite a while, but the Blue Wool test does not
appear to
> be the internationally accepted standard for photos or inkjet
pigments.
>
> Let me quote Lyson:
>
> "Lyson has a number of methods for observing pictorial image fading of
which
> Blue Wool and simple window placement are still carried out. However,
the
> test that we believe gives the most accurate prediction of actual
indoor
> display life is the method used by Wilhelm Imaging Research, Inc
> (www.wilhelm-research.com). The Wilhelm test criteria has, in the
main, been
> adopted into the 1996 ANSI (American National Standards Institute)
document
> 'Stability of Colour Pictorial Images', which itself is in the process
of
> being furthered into an ISO standard. By definition, this will become
the
> International test that our industry should orientate itself to."
> http://www.nazdar.com/Lyson/lyson-longevity.html
>
> I actually have the Blue Wool test materials and decided not to bother
with
> them.  I'm not saying they are not relevant, but they do not give
enough
> information to distinguish the inks, and testing to the end stage is
not
> what I'm most interested in and is not practical for me.  I do not
have the
> time to do that for enough inks and papers to allow me to move forward
at
> the speed this industry moves.
>
> Let's look at some actual numbers and equivalences.  The Blue Wool
rating of
> 7 is 300 megalux hours of exposure before fading becomes noticeable. 
(See,
> for example, http://www.handprint.com/HP/WCL/pigmt6.html#lightfast) 
This
> translates into 152 Wilhelm years of display.  (Wilhelm uses 450 lux
for 12
> hours per day.)  The Blue Wool rating of 8 (the highest) is 900
megalux
> hours of exposure before fading becomes noticeable.  This is 457
Wilhelm
> years of display.
>
> Most of the action with respect to the pigments I'm working with is
between
> the BW 7 and 8 ratings.  That is rather large gap -- from 152 to 457
Wilhelm
> years of display.
>
> It also would simply take me too long to test to the end points, and I
don't
> think that is my main interest anyway.  So, I test for shorter
periods, but
> long enough that the initial high non-linearity I've found with some
inks
> does not overwhelm the final results.  (Most of this is in the first
> "Wilhelm" year.)
>
> As an example, in one test a bit more than a year ago, I exposed
samples for
> what would be the equivalent of 13 Wilhelm years.  In this test the
MIS UT7
> did 2.8 times better (looking at the change in Lab L) than the K3 B&W
inks
> on Premier Art Hot Press (the same coating as UltraSmooth).  Wilhelm
rates
> the K3 B&W inks at ">205" years on UltraSmooth under glass (not UV
glass).
> So, could the UT7 inks really "last" 574 years in typical indoor
display?  I
> don't know, and I'm not going to do the testing needed to get to that
stage.
> That would, by the way, be a Blue Wool rating of 8.  In fact, Livick
did a
> test on coated UT inks all the way out to the end point.  He came up
with a
> rating of 681 years.
>
> Any accelerated test is subject to criticism.  They all introduce
factors
> that might skew the results one way or the other.  But when I see most
of
> the industry going to Wilhelm, that makes his procedures the de facto
> standards regardless of their merits.  In fact, however, my reading
and
> experience suggests Wilhelm is the best there is.
>
> At any rate, I simply want to point out that Blue Wool rating of 7 is
fine,
> but it does not tell me what I'm looking for.  It does not tell me
these new
> inks are any different than the others that are out there.
>
> I'd love to see a comparative test. I really hope you do have
something
> special.
>
> Epson's Claria "dye" inks demonstrate rather convincingly that
significant
> progress is possible and perhaps likely in this field.  The pigments
we use
> are called "dye stacks."  I wonder what happens when Epson "stacks"
the
> Claria dyes?  Would there be a huge (like 4x) improvement in the
pigment
> lightfastness the way there appears to be for the dyes in their
soluble
> form?  Would we be looking at color prints with "800 years" of display
life?
>
> Paul
> www.PaulRoark.com
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>