Digital BW, The Print

Here are some numbers that may confuse as much as enlighten.

I loaded the 2200 Photo K in my 1160 and printed some 100% black patches to
look at the dmax.  Since I had recently received both EEM and EAM from
Atlex, I printed the Photo K on both, and they were equal.

I also used the X-Rite to measure the front and back brightness of the new
EAM and EEM.  With these samples, the EAM actually had a brighter front and
back than the EEM -- just the opposite of what I'd seen comparing old EAM
with EEM.  So, I'm guessing the change in formula, if any, occurred prior to
the change in name, and there are sample differences that affect both.  I
note also that outside the U.S. EAM is still, apparently, being sold.

The dmax of the 2200 Photo K, in "black only" printing, HW Matte paper
setting was as follows:

2200 Photo K-only, EEM & EAM, 1160 -- 1.41.

For comparison, here is the dmax of an Archival K sample:

7500 Archival K-only, EAM, 1160 -- 1.49.

It is possible that the EAM paper batch differences account for some of this
higher Archival Black dmax.  It may also be that the Photo black will darken
over the next 24 hours.  (I usually expect about 0.01 increase in density
after a day.)

However, this as well as other comparisons of these inks seems to indicate
that the 2200 Photo black is not darker than the Archival black.  Yet,
according to the Material Safety Data Sheets, both inks have "<3%" carbon
black, and the Photo black also has "<5%" "Proprietary dyes and pigments."
Perhaps these make a difference on RC papers, but on EEM & EAM the
additional "proprietary dyes and pigments" seem to make no positive
contribution.

Alternatively, the MSDSs may be next to worthless in trying to compare inks.
Perhaps Archival K has 2.99% carbon black and Photo K has 0.001% carbon
black.  Both sheets would be technically accurate, but the way the numbers
are listed might simply be there to confuse competitors.

Perhaps the changes in the Photo K formula relative to Archival K have more
to do with cutting costs or other goals, as opposed to increasing dmax.

Paul
http://www.PaulRoark.com