Digital BW, The Print

Barry,

You wrote:

>Are you suggesting that the errors in Jon Cones results might be
>deliberately biased towards his inks?

No, I think there could have been an innocent mistake.  I'll send a copy of
my posting directly to Cone.  Hopefully the issue will be clarified quickly.

Paul
http://www.PaulRoark.com
_______________________________________________

--- In DigitalBlackandWhiteThePrint@y..., "Paul Roark"
<paul.roark@v...> wrote:
> Robert,
>
> You wrote:
>
> >Finally a manufacturer published actual test results.
>
> It is good to see some data.  I've always liked the fact that MIS
published
> its RIT test results for the MIS Archival inks.
>
> It looks like there may be an error in the MIS FS delta E
calculation in the
> fade results Cone Editions released.  The FS K faded less than the
Portfolio
> black, yet is listed as having a higher delta e.
>
> I'm also not sure about note 3 on the "Test Condition."  It says,
> "Lightfastness: Irradiation UV (Xe) 10,000 Kj/m2/200 hours."
>
> If the lamp was strong UV, then I wonder if the results correlate
well with
> actual lighting.  Most of us are oriented to indoor display, where
the UV
> from fluorescent lights or window-filtered (thus no deep UV) light
is the
> main problem.  Unlike the outdoor signage market, I don't think we
have that
> much of a UV problem with our prints.
>
> I'm a little surprised that the carbon sepia did not do better.  I
would
> have thought that an ink that was supposed to be pure carbon would
fade less
> than inks that have some color pigments in them to get the tones
that are

> popular.
>
> I'll run my own tests as samples are provided.
>
> Paul
> http://www.PaulRoark.com
> ______________________________________
>
> From: piezography3000@y...
> Reply-To: piezography3000@y...
> Date: 7 Nov 2002 03:12:17 -0000
> To: piezography3000@y...
> Subject: [piezoBW] New file uploaded to piezography3000
>
>
> Hello,
>
> This email message is a notification to let you know that
> a file has been uploaded to the Files area of the piezography3000
> group.
>
>   File        : /400 Hour Xenon tests/preliminary-xenon.pdf
>   Uploaded by : piezobw <piezobw@c...>
>   Description : 400 hours on EPSON EAM
>
> You can access this file at the URL
>
> http://groups.yahoo.com/group/piezography3000/files/
> 400%20Hour%20Xenon%20tests/preliminary-xenon.pdf
>
> [cut and paste the last part of the URL]

--- In DigitalBlackandWhiteThePrint@y..., "Paul Roark" <paul.roark@v...> 
wrote:
> Barry,
> 
> You wrote:
> 
> >Are you suggesting that the errors in Jon Cones results might be
> >deliberately biased towards his inks?
> 
> No, I think there could have been an innocent mistake.  I'll send a copy of
> my posting directly to Cone.  Hopefully the issue will be clarified quickly.


The clarification is not necessary, but this is quick. Delta E is a reference to 
color shift, not fade. The upper part of the tests show fade as loss of density 
measured in %. The lower part of the tests show color shift as mesaured in 
Delta E. Paul must have seen the Density Loss and Delta E as the same for 
some reason and thought it did not compute. But they are totally separate. I 
am sure that that was an innocent mistake.

Why would MIS FS-black  fade just slightly less than Portfolio Black but have 
more measurable color shift as described in Delta E? MIS-FS black is 
comprised of minimum 10% AZO dye to temper the warmth of the carbon and 
add density. MIS-FS carbon is warmer than the carbon in Portfolio Black. 
Portfolio Black uses 8% metal complex and the more "neutral" carbon color in 
conjunction with a similar color metal complex results in less color shift in the 
black. 

In regards to UV light: pigments are susceptible to UV wave length while dye 
and metal complex are more susceptible to visible spectrum. If there were no 
windows in the world and sunlight (heavy UV) was not a factor to be dealt 
with, we could bias the tests towards safer lights and both MIS-FS and 
Portfolio Black would fair better. But we know from experience that it is wiser 
to make the tests tough. Additionally, the Xenon chamber is an industry 
standards that any manufacturer can duplicate. Nearly every university has 
one somewhere on campus if they do research.

Fade is fade as far as we are concerned. We will upload more tests from other 
testers as well as RIT shortly. Our goal is to determine how long an EPSON 
year is in doggie years - and then correlate that with human years. We know 
that the 200 year, and 75 year, and 25 year EPSON inks show perceptible 
fade in our own studios in less than a year. The predictions made by the big 
two are in years and we want to eventually tie that into measurable fade with 
these type of tests, so that consumers can make educated decisions. 
Eventually perhaps, the predictions will fade and the real world data will be 
presented.


Jon Cone
Piezography Brand Software and Inks