Re: Epson 2200 inks
Re: Epson 2200 inks
- Subject: Re: Epson 2200 inks
- From: John Ward <email@hidden>
- Date: Tue, 20 Jan 2004 18:02:42 -0700
On Thu, 15 Jan 2004 09:11:21 -0500 Roger Breton posted short term color
change results for Epson 2200 Ultrachrome inks with matte black on Epson
Enhanced Matte paper. The question was extended to the 76/9600 printers
using the same inks. A number of people qualitatively confirmed his
results.
Being ever late to the party, the purpose of this post is to share my
results for three papers and two ink systems. These show that short term
changes depend significantly on media as well as ink type as is
generally well known. For me, the implications for profiling are to wait
at least 48 hours -- and longer with some systems.
Roger wrote:
>
1st set of measurements after 15 minutes of drying
>
2nd set of measurements after 2 days of drying
>
>
Average Delta E:
>
Overall 0.31
>
Best 90% 0.28
>
Worst 10% 0.55
I use the TC2.88 target instead of the TC9.18 and make the first
measurement 1 hour after printing to reduce variations over the target
due to actual print time and the time it takes me to do the EyeOnePro
spectral measurements. Data points are averages of two readings of the
target and a curve is fit to measurements made over an 8 day period. The
target printouts age at approximately 67F (19.4C) and 30%RH (relative
humidity) exposed to ambient air and tungsten office light. The average
deltaE values are calculated relative to the first measurement one hour
after printing.
For the Epson 7600 Ultrachrome inks (matte black) on Enhanced Matte, my
48 hour (after printing) average deltaE is 0.33 which is in remarkable
agreement with Roger -- a bit too good in fact since his measurement is
relative to approximately the first 15 minutes when things are changing
rapidly. Over the first hour I estimate an average deltaE change of 0.07
so a more comparable figure to Roger's would be 0.38 -- still not bad.
My data points closest to Roger's 48 hour point were at 33 and 56 hours.
This is getting pretty slippery but using linear interpolation between
my points to estimate best 90% and worst 10% average deltaEs
corresponding to Roger's overall value of 0.31 gives 0.27 for the best
90% and 0.73 for the worst 10%. The latter seems noticeably worse than
Roger's but may reflect the different sized targets. All and all, I
still think the agreement is pretty good.
For the same printer and inks on Hahnem|hle Photo Rag 308 paper the 48
hour average deltaE is 0.59. Using the Epson 1270 with dye inks on Epson
Matte Paper Heavyweight the 48 hour average deltaE is 1.13.
Enhanced Matte looks really good but these figures do not tell the whole
story. The average deltaE change curve for Enhanced Matte has a very
different shape from the other two systems. The 48 hour change for
Ultrachrome ink (matte black) on Photo Rag is 82% of the total change
out to 8 days and there is only 0.036 change after 4 days. Similarly,
with the dye inks on Matte Heavyweight the 48 hour change is 78% of the
total change out to 8 days and there is 0.036 change after 6 days. Both
of these change curves are getting very flat by 8 days.
However, for Ultrachrome (matte black) inks on Enhanced Matte the 48
hour change is only 51% of the total 8 day change and at 8 days it is
still increasing at a fairly steady rate of 0.020 per day. A follow-up
20 day reading showed the 48 hour change to be 40% of the 20 day change.
I am not really sure where this paper/ink combination quits changing.
All of these details are probably buried in the notebooks of many people
on this list but I hope these figures will at least be of interest to
some of the lurkers -- of which I am mostly one. Since I read in digest,
I do appreciate direct cc for any comments.
John Ward
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