Greg,
Please look at the Files section of
this forum. There, in the folder Docs, you will find a folder called QTR Files for
Digital Negatives where I talk about two different methods of profiling that I
use, one for an all gray ink set, the other for a single gray value system
where I use the Epson OEM inks. I call that Carbon 100 because it is very easy
and simple to explain to students. Like English 101 or French 101 in college!!
Basically, I only use three of the 8 inks in an Epson K3 ink set (PK, Y and
LLK) because these are the only ones that block UV light. All of the others I
set to defalt level of 1 so that the printer uses some of the ink to inks to
keep the nozzles happy. The default level of the PK, Y and LLK is set relative
to each other based on the UV blocking power of each. PK and Y are
approximately equal so I set them at the same value, LLK needs about 2X the
percentage of PK and Y to lay down the same UV blocking, so I set the default
ink level to twice the percentage. In the Carbon 100 profile in the Files section
I have these values set to PK=25, Y=25 and LLK=50, and in that profile you get
UV blocking that gives a density range of about log 2.05 on OHP. If that DR
turns out to be too high for your process you decrease the number of these
three inks proportionally, say -10%, or -20%, etc. If these limits give a
negative with a density range too low for your process you increase the number
of these three inks by proportionally, for example by +10% or +20%.
Basically, you adjust the ink percentage of the PK, Y and LLK until you can
print a step wedge negative (ising your standard printing time) that has
a full range of tones from DMax to DMin. Then you can linearize the profile,
your method with the Spyder 4 and Richard's spread sheet is a good way, or you
can also just enter the log density numbers in the LINEARIZE command, as I do
in the sample Carbon 100 profile in the Files section.
Sandy