Digital BW, The Print

Tyler wrote:

>...
>Partitioning, the way the term tends to be used here, and how I think
>of it, has more to do with traditional quad inksets, and is expanded
>from there to account for other inksets. So in it's more basic form,
>it has to do with sending the appropriate part of the tonal scale in
>the image to the appropriate gray ink, 

The Epson driver regularly "partitions" the inks between the light and dark
magenta and cyan, the colors and black, and now the light and dark black.

One reason I prefer to put my value-added on top of the Epson driver is that
I believe Epson does an outstanding job of partitioning its inks. 

I believe Jon Cone's ICC system is also using the Epson driver.

>Since [the Epson driver] works with RGB input, 
>everything must be done with RGB curves.

Yes, and I find this rather convenient, open, flexible, and, of course,
cheap.  With the newest inksets, because I've made inksets that basically
follow Epson's lead, the Epson driver does most of the heavy lifting with
respect to partitioning.  In fact, the inks can be printed with no curves at
all.  Writing curves for the newest inksets is much easier than it used to
be.

>There isn't a straight through path from the file to the
>specific inks, ...

Being able to print with no curves and no special software seems like a very
direct path.

However, it's true that the Epson driver does not give me total control of
every jet.  There might, indeed, be circumstances where I'd take advantage
of such control, and, overall, I'd probably prefer CMYK to RGB.

If I were a pro shop doing color work, I'd probably have a 9600 with a good
RIP so that I could do both B&W and Color display prints with the machine.  

However, my medium is B&W.  With a dedicated B&W inkset, including both
monotone and variable-tone approaches, I think the Epson driver can deliver
excellent results.

>...
>Not only do you have no direct control of the black
>ink (you have to control it with specific RGB numbers) ...

Yes, but this really is not much of a problem.  

> some RGB values will cause density to go down instead of up the 
>way we are attempting to control it. ...

This happens when the total ink load has reached the driver's limit for the
paper type designated.  If I then try to darken the image with a relatively
light ink, the driver puts in more of the light ink but pulls out an equal
amount of the dark ink.  So, the image gets lighter instead of darker. 

Where there are 2 inks, using the darker one or moving them both tends to
avoid the problem.  With the UT2 & 7 inksets I don't run into this issue
very often.  

I'm not saying most will want to get into the curves, but experienced users
will find the job has gotten easier.  That is part of what I'm doing with
these inksets.

>... I wound up doing a lot of trial and error...

Yes, so did I, and I still do some.  I generally find it takes 6 test strips
to make a new profile for a new paper.  That's one letter-size sheet or
paper.  Of course, those who have not done this might find it very
frustrating, but for those who are accustomed to the curves approach, the
job has gotten easier.

Again, however, if I was a business that could pass the cost onto customers,
I might find there is an easier way that would be more efficient for me.  As
a B&W printer for my own uses, however, the cost effectiveness and openness
of the Epson driver is going to be hard to beat.

Paul
www.PaulRoark.com 

For UT2 information, curves, and settings see:
http://home1.gte.net/res09aij/