Rik,
The numbers in these charts do not coincide with what I've measured or with
how the inksets were designed.
>http://www.inkjetmall.com/store/info/1000-hours.html
Note that the fade tests here compare the new PiezoTone to the old FS, not
the UT-FS or UT-FSN. They have no bearing on the UT family of inks.
The chart does, however, show that the FS and PiezoTone densities are about
the same. They were designed to be the same, and they print with the same
drivers and curves. So, as a starting point, I'd assume that FS and
PiezoTone ODs are the same.
The explanation of the Piezo test says, "All of the monochromatic inks were
printed in patches of gray or black. The color inks were printed in patches
of their full hue..."
The test patches for the grays were not at full strength. See the obvious
discrepancy that the UC yellow has a higher OD than the dark gray PT - no
way. In fact, note that the UC Yellow in the InkJetMall table has a higher
OD than the UltraChrome M or C - no way. The fade rate of the UC cyan
(which the table spells "cyanine") is said to be the higher than the Y or M.
Again, contrary to my tests and RIT tests of the MIS "Archival" pigments.
See the graph of the RIT fade results here:
http://www.inksupply.com/index.cfm?source=html/rit.html .
Bottom line, I don't put a lot of weight in the InkJetMall chart.
The MIS chart at
>http://www.inksupply.com/index.cfm?source=html/utfadedata.html
is for the UT1 variable-tone inkset. The numbers are close to what I get
with the X-Rite spectrophotometer (at least where there is not an obvious
mistake in the UT-LC).
>Below, I show the data just for Hahnemuhle Photo Rag paper...
>The O.D.'s for the PiezoTone inks (Warm Neutral though the other ink
>sets are similar) are as follows:
>Light gray: 0.138
>Medium gray: 0.241
>Dark gray: 0.711
>Black: 1.720/1.780 (Museum/Portfolio)
The grays above are not at 100% density. It's possible the "Color
Management" in the Epson driver was set to "Color Controls."
>The O.D.'s for the UT inks are as follows:
>UT-Y (25% Black): 0.500
>UT-M (cool toner): 0.600
>UT-LM (light cool toner): 0.640
>UT-LC (50% Black): 1.340
>UT-C (75% Black): 1.330
>UT-LK (Light Black): 1.270
>UT-K (Eboni): 1.750
These are close to what one would get if the printer pumped out 100% with
"No Color Adjustment."
>Based on this data, there are a few conclusions that I draw:
>- the lightest UT ink (UT-Y, "25% Black") is far darker than the
>lightest two PiezoTone inks ...
No. In fact the UT1 Y in a hextone set (which is the M in the quad set) was
the lightest gray a 4-ink printer could have and still have a cold toner.
The lightest gray was set to a value between the Piezo/FS Y and M densities.
On an 1160, which was the printer I then had and designed the inkset for, it
prints dotless.
>- the UT-LC ("50% Black") and UT-C ("75% Black") inks have essentially
>the same density,
No, the MIS chart is in error. The UT1-LC is a 50% dilution of the UT1-C.
The density give for the UT-C is the correct. The UT-C is the basic density
of the dark grays in the PiezoTone and the UT family of inks. The dark
grays are all about the same density.
> which strangely enough, is lighter than the UT-LK ("Light Black") ink.
No the LK is lighter than the UT-C (1.24 for LK, 1.32 for UT-C in the MIS
chart).
>- The Ultratones have essentially three densities:
>1) around 0.5-0.6; 2) around 1.3; and 3) black.
MIS left out the LC & LM for some reason. They are both 50% dilutions of
the C & M, respectively.
>- The Piezotones have four densities
>1) around 0.15; 2) around 0.24; 3) around 0.7; and 4) black.
The PiezoTone/FS densities of the Y & M are slightly below and above the UT1
lightest gray, and they are all very close. That is one of the things I
finally changed for my 7500UT-FSN setup. I've moved the M (now LC in the
7500 set) to a position that is closer to half way between the lightest and
darkest Piezo/FS densities.
>... what differences do you see in the final output based on
>these different philosophies?
The Piezo and FS densities are the same and they print the same.
The UT1 is an older variable tone that had a light gray that was slightly
darker than the FS-Y. The lightest toner in the hextone set (LM) was
extremely light. The 1280 with the UT1 inkset had the smoothest highlights
I've measured, using a 1600 dpi scanner and the histogram standard deviation
tool.
The UT1 in a quad (4-ink printer) does show more dots in the neutral or cool
prints due to there being only one toner. Most found it fine in an 1160,
but in my 3000 I preferred the VMS with the old inks and the UT-FSN with the
newer inks.
The Piezo/FS/UT-FS inks can produce a print that is slightly smoother than
the current UT2 and UT7 inksets unless the optional Y position has a light
ink in it. In my 7500, for example, I use the FSN-Y in the Y position to
get perfectly dotless highlights (even with a loupe). Most, however, will
never see the dots in the UT2 and UT7 inksets in actual prints.
The higher densities are in there for several reasons. First, they allow
the printers to print good B&W with virtually no workflow. Second, they are
needed to avoid overloading the glossy papers. Third, they are needed to
achieve the tone range from cold to sepia. But, I've noted regularly that
for those who do not use sepia, that spot has other uses -- another light
carbon for better lightfastness, glop for bronze-less glossy prints, custom
tone inks, and, as relevant to this question, a very light gray for more
smoothness.
I think modern printers do a great job with fewer and more dense inks. So,
I use the UT2 and UT7 spots currently for glop in my printers, whereas the
old non-variable-dot 7500 can't quite do the job without the light UT-FSN-Y
ink.
Hope this helps.
Paul
www.PaulRoark.com