Digital BW, The Print

JB,

I really don't see that Wilhelm and RIT are any less "anecdotal." 
Actually I find them worse because they try to extrapolate their data 
into a statement about longevity in years.

I believe that Paul's test is a valid comparison of the INK/PAPER 
combinations. It is not a valid comparison of Piezo to MIS VM. It is 
a valid comparison of the MIS VM and VM X3 inks.

These types of test are of interest if you view them as comparative 
testing and not absolute testing. The more people who engage in their 
own testing and share their results the better. As the amount of 
information grows it may be possible to spot trends.


I think you are mistaken to categorically question the testing of 
the "home enthusiast." The members of the list have a great deal of 
expertise in many areas.

I am very puzzled as to what your reasons are to question Paul's 
motivation and integrity. He has done a great deal of work with the 
inks and shared the information freely. I do not understand your 
antagonism.

Martin Wesley


--- In DigitalBlackandWhiteThePrint@y..., jbroyaliii@h... wrote:
> The competence of the home enthusiast via-a-vis the facilities
> dedicated to testing and reporting image permanence of digital 
> and traditional photographic print materials (i.e., Wilhelm, RIT)
> has relegated the reports from home to the anecdotal.
> 
> Unfortunately, this latest broadcast, which compares two inks
> printed on different media, not only brings to question the 
> competence, but also the motivation and integrity of the tester.
> 
> JB
> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@y..., Robert Morrison 
> <rmorrison@p...> wrote:
> > Ditto, seems rather strange.  Why didn't you just print Piezo on 
> EAM?
> > 
> > Also...with regards to Steadman's note....it is absolutely 
critical 
> that
> > prints are made at the same time because of natural warming that 
> occurs...at
> > least with Piezo (don't know about the MIS inks).  Starting a 
fade 
> at Print
> > Time = 0 and Print Time = 2 weeks will certainly yield different 
> results.
> > 
> > Robert
> > 
> > On 10/17/01 7:21 AM, "Cathy Van Berg" <vanbergc@y...> wrote:
> > 
> > > Let me make sure I'm understanding this correctly...
> > > 
> > > You printed Piezo and MIS VM/VM X3 on different papers for this 
> test?
> > > If that is true, then you cannot draw valid conclusions by 
> comparing
> > > what I see as apples and oranges... You may say that for a given
> > > paper, these inks fade x amount, but you cannot compare them to 
> each
> > > other. If it was not your intent to compare fading and warming 
> between
> > > the inks, then that was not clear to me...
> > > 
> > > Thanks,
> > > Cathy
> > > 
> > > 
> > > 
> > > --- In DigitalBlackandWhiteThePrint@y..., "Paul Roark"
> > > <paul.roark@v...> wrote:
> > >> In the latest fade test series, I put test strips of Piezo on 
> Hahnemuhle
> > >> German Etching, MIS VM (nc curve) on EAM, and an experimental
> > > variable-tone
> > >> called VM X3 that prints with the same curves as MIS VM (nc 
> curve).
> > >> 
> > >> I measured fading as a percentage of the starting value and 
> warming
> > > as the
> > >> change in the difference between the RGB red and blue channel
> > > measures.  The
> > >> test strips were scanned into Photoshop with an Epson 1600, 
and 
> the
> > >> Histogram tool was used to make the measurements.
> > >> 
> > >> 0% (paper white) warming:  EAM (2 samples) 2.4 & 2.3 units;  
> German
> > > Etching
> > >> 0.6 units.
> > >> 
> > >> 50% patch measures:
> > >> 
> > >> Piezo on German Etching -- Warming = 10.3 units,   Fading = 
9.2%
> > >> 
> > >> MIS VM on EAM           -- Warming = 9 units,      Fading = 
6.9%
> > >> 
> > >> VM X3 on EAM            -- Warming = 3.1 units,    Fading = 5%
> > >> 
> > >> Note that most of the warming had taken place by the 100 hour 
> mark.  The
> > >> fading was also fastest at first, but it continues much more 
so 
> than the
> > >> warming.
> > >> 
> > >> The fading of the 90% patch needs to be mentioned.  I measure 
the
> > > 90% patch
> > >> as opposed to the pure 100% patch to see what the shadows will 
> be doing
> > >> because it may indicate whether there is a negative interaction
> > > between the
> > >> black ink and something in the midtone inks (and, of course, 
the
> > > paper is a
> > >> huge factor that affects all the patches).  A number of people 
> have
> > > noted
> > >> that some components, perhaps including dyes, can actually act 
as
> > > catalysts
> > >> in fading other components, for example, the black ink.
> > >> 
> > >> (Note that in my fader the light is intense, so the black 
> patches are
> > >> undoubtedly warmer than the lighter patches.  This is probably 
> also
> > > the case
> > >> in the "south window tests" and perhaps all accelerated fade 
> tests.  One
> > >> would expect, therefore, to see more fading in the darker 
> patches.)
> > >> 
> > >> To measure the fading of the 90% patch, I converted the mode to
> > > grayscale
> > >> and used levels to set the white and black points of the 
control
> > > strips as
> > >> accurately as possible.  The percentage of fading is a 
> percentage of
> > > the 90%
> > >> control strip for each set.  (The MIS VM and X3 are about the 
> same.)
> > >> 
> > >> 90% patch fading:
> > >> 
> > >> Piezo on German Etching -- 55%
> > >> 
> > >> VM X3 on EAM -- 18%.
> > >> 
> > >> Also of note, the Piezo 7000 black on the German Etching paper 
is
> > > slightly
> > >> darker than the MIS VM black on EAM printed with either the 
3000 
> or
> > > 1160.
> > >> When the levels sets the Piezo/German Etching black on 100%, 
the 
> MIS VM
> > >> blacks read 98%.
> > >> 
> > >> I have sent a Jpeg of the scans to Martin for inclusion in the 
> Message
> > >> Related Files section of the forum.  I did notice, however, 
that 
> the
> > > Jpeg
> > >> compression slightly affected the measures.  So, measuring 
those
> > > Jpegs may
> > >> result in slightly different readings than above.
> > >> 
> > >> Paul
> > >> http://www.PaulRoark.com
> > > 
> > > 
> > > 
> > > Please visit the Group Homepage to check the Files, Bookmarks, 
> Polls and other
> > > resources as they are often being updated. The page is at:
> > > 
> > > http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint
> > > 
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> > > 
> > 
> > ----------------------
> > Robert Morrison
> > rmorrison@p...
> > 
> > 310-397-2704
> > 
> > 4131 Bledsoe Ave.
> > Los Angeles, CA 90066