Digital BW, The Print

David ... <david@...> wrote:

**
>
> ... Any and all information about adding color pigment to a carbon ink set
> would be greatly appreciated.
>
Short answer:  Searching this forum with it's search capabilities and the
web will probably get you the best information.

I do not recommend most people do any more than dilute existing inks.  It
is much safer to use color inks in separate channels.  That opens up the
color issues to a lot of competitive alternatives and avoids many issues of
mixing different pigment types.

(I don't know which MIS article you saw.  I asked MIS to remove from their
"Roark's lab" page material that they had added that did not represent my
views.  That may have been what you saw.  I have not checked it recently
for accuracy.  It's not a page I write.)


Long answer:

I designed the MIS B&W inkset not as a contractor  for or under the control
of MIS, but as an independent photographer and printer who wanted something
that did not exist.  My formulas have mostly been published.  Bob Zeiss
(the founder of MIS) and I shared information regularly, mostly verbally.
 There was never a published manual on ink mixing, as such, from that
collaboration, aside from what you can access via this forum and web
searches (including of my pages).

The MIS toned inks are very good for most enthusiasts who use a desktop
printer.  However, note that I moved away from them.  (My older PDFs etc.
may not reflect my current views.  There has been progress and learning.)
Differential fade and ink separation/settlement issues made them less than
ideal for wide format printers and fine art or museum quality printing,
including longevity.  Getting good carbon inks is much easier for a small
company than getting top notch color pigments.   Particularly when you look
at the issues of blending and differential fade.

From a chemical compatibility point of view, there is a huge leap in
complexity between (1) mixing a generic base and (2) grinding/coating the
particles with compatible, carefully-matched electrostatic dispersal
chemicals.  The big companies have vastly more technical resources and
economies of scale compared to the small ink sellers (or me).  These
economies of scale have given the OEMs advantages with respect to both the
color inks and blended carbon + color inks.  This is not to say that a
small company cannot tap into a non-OEM chemical company to do this work,
but in the past the OEMs held the high ground on color pigments and blends.


You'll note in my latest inksets, I use MIS carbon, and I use Epson color
or HP blended gray inks in separate channels.  Having inks is separate
channels avoids many problems.  Also, software (making profiles) is a more
flexible approach than color-carbon blending.

What we and a number of others did in the past is just use the Image
Specialists' color and carbon pigments that were available.  Their previous
chemist and their suppliers handled all the issues relating to, for
example, the pigments' coatings and base.  The color and glossy carbon inks
from IS & MIS mixed well and were relatively compatible.  They used the
same base, but they were never designed explicitly with the mixing in mind.
They were, also, not matched very well with respect to fade
characteristics.  (Check http://www.aardenburg-imaging.com/.)

HP, from what I can see, makes the best blended carbon + color neutral/cool
ink.  Fade tests and centrifuge testing (I use a medical counter-top unit)
shows good matching of the pigments' characteristics.  I like its color,
and it dilutes well with the generic base (or even MIS's amber base - for
reducing bronzing).  I use it diluted with the generic base to cool Eboni
(in separate channels).

MIS is now taking a shot at some new, upgraded blended inks like HP's.  I
have them in beta, but it's way too early to know much more than the tone
is good and they appear to print very much like the older IS pigments.  MIS
is doing fade testing now, and I'll do a centrifuge test for separation as
well as other tests.  (I've found the centrifuge test results correlate
well with my real world experiences with color separation and settling.)

For now, the only ink mixing that I recommend for most is, first, use of
available bases to dilute existing pigments without blending. Second, my
experience is that the MIS K4 inkset glossy inks can all be mixed together
with good results for Epson desktop printers.  (3800 and up will probably
experience some blended ink separation in the carts and tubing, causing
some print tone drift.)   Mix the MIS glossy color inks only with the MIS
glossy carbon inks (LK, etc, as well as the MIS UltraTone carbons).

The basic dilution ratio for dark to light is about 30% darker ink to 70%
base.  A 1:2 mixing ratio is easiest if accurate (0.1 gram) digital scales
are not available.  I've been able to make good cross-overs from about 50%
to 20% on the dilution steps.

The PK and MK inks have different densities on matte paper; MK is darker.
 So, the PK-LK-LLK (standard 30/70 dilution) will result in a different and
lighter set of matte densities than an MK-30%MK-9%MK progression.

The early B&W inksets were matte paper only and often used a matte paper
progression, particularly for the first density jump --  MK to 30%MK.  What
I call UT-C is at the "30% MK" density point.  UT-C is, however, made with
glossy MIS carbon.  Eboni-6 "C" (30% Eboni) is also at this printed density
point (although the original MK was not Eboni).  There has been some drift
in the densities and dilution ratios.

(Note that the ink-load/print-density curves are not congruent for
different pigment types, but they generally all declining slope curves.
 So, if you want to match inks, you often only match the densities at only
one point on the curve (aside from zero).)

The MIS glossy carbon inksets for color printing in K3 Epson printers use
the PK-30%PK etc. spacing.

For Eboni/Carbon-6 I decided to use the two standard MK and PK density
progressions that I'd used in the MIS inkset.  I was familiar with them and
they printed well.  It keeps the profiles more compatible also.  At any
rate, I ended up with 2 staggered, somewhat standard progressions for
Eboni-6.  Eb6-Y (2% Eboni), while lighter than any 100% carbon ink MIS has
in its glossy carbon sets, is a relatively standard dilution jump away from
the next lightest. (I round off to keep things simple for my scales/weight
based mixing.)

I hope some of this background is useful.

Paul
www.PaulRoark.com


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