Digital BW, The Print

I'm not going to get into which approach is best, but I thought I'd comment
on a few issues.

> new2jazz04 wrote:
> 
> > ... I just purchased the
> > Piezography K7 inkset for my 2200 and have been really pleased with
> > the results so far...

> >      I have not had experience with the MIS ink systems and was
> > wondering whether someone could compare the relative pro's and con's
> > of that system to the K7 system

Bruce wrote:

> 
> IMHO, it really comes down to whether you want a fixed tone inkset or a
> variable tone inkset.

Price is also a relevant factor.  Both systems can work very well.

(Also, note that MIS has monotone inksets, like the new R2 for the R220.)

 
> The main reason to use the UT7 set [the MIS variable-tone inkset 
> for the 2200] is that you can vary the tone to
> suit, within reason.

This includes the flexibility to "profile" different papers so that they
print with the tone you like on any number of papers.

> The main disadvantage is the possibility of
> differential fading over time pushing the print's tone warmer or cooler
> than you intended.

No, there should be no significant difference here.  I believe the K7 inks
have differing amounts of color pigments mixed in.  I may be wrong here, but
I simply don't know of any pure carbon pigments that can print neutral over
the entire range of densities we're interested in.  It'll really take
controlled, comparative fade testing to see what, if any, aging differences
there are from these inksets.  The differential fading problem occurs with
color inksets that attempt to make a gray tone from color inks.

A "neutral" tone that is composed of predominantly carbon will usually have
some color pigments mixed in.  These will fade faster than the carbon, but
the carbon also shifts color.  So, there will be color change in either
case.  What usually dominates in a reasonable time span (like one's expected
life span for normal display conditions) is the warming of the carbon.  (If
you're using brightened paper, the burning out of the optical brighteners
may be the largest change -- which is a big reason I prefer paper with no
OBAs.)


> The K7 inkset has several advantages. The seven dilutions can give
> smoother tonal transitions than a four dilution set...

The more different densities, the smoother one can make a print, at least in
theory.  There are diminishing returns here.  Also, how the curves are
written, the dither pattern of the printer and driver, and how well the
printer is working might overcome the advantages of more densities rather
quickly.  In general, Jon Cone has stressed ultimate smoothness, whereas
with the inksets I've made for myself (and MIS sells -- royalty free), I
tend to prefer more flexibility or other factors after I think the inkset is
so smooth there will be no practical difference in final visual impact.

> ... Since the K7 set is a set of dilutions of a common black,
> tonality will be the same as the inks age.

I doubt the K7 is simply different dilutions of a single black.  Different
dilutions need different toning to produce the same final hue on the printed
page.  It's not nearly as simple as just making different dilutions.  I
suspect the designers of the K7 inkset put a lot of effort into tuning this
inkset to achieve their target tones across as much of the dynamic range of
the printed image as possible.

> There should be no
> differential fading over time that will change the color of the print.

As noted above, there should not be differential fading with any of these
dedicated B&W inksets, but with time there will be some minor shifts due, in
large part, to the way the carbon and paper age.  Everything ultimately
fades, but these inksets are so good I would not worry about it (unless
you're in direct sun or outside).

> You don't have to spend time and resources (test prints) picking a tone
> - the tone is fixed. Because the tone of the ink is fixed, you can vary
> the tone of the print by varying the tone of the paper.

Many people prefer monotone inksets.  They are simpler to use.  That is a
big reason for the R220 R2 system being monotone (but with the ability to
change tones by putting in differing combinations of ink cartridges).  

As Bruce noted initially, to me the real issue is whether one wants a
variable-tone inkset or not.  I like both, and both have different
advantages.  The R2 is my latest, and it's monotone.  On the other hand, for
the 2400 I'm going for more control than the UT2 or UT7 (but probably no
sepia).  Many have no interest in tuning their inksets, but I do.  With the
2400 I think I can bring this ability to tune and profile a B&W inkset to a
new level.  It's a challenge I look forward to in 2006.

Happy New Year.

Paul
www.PaulRoark.com