Digital BW, The Print

David,

**
> ...I will have two ink stations unused ... C and LC.
>
> Do I understand correctly, that if I want a heavy brown tone with my carbon
> ink system, I would be better off putting magenta and yellow (right colors
> I
> presume?), respectively, into the C and LC spots rather than mixing them
> directly into the carbon inks?
>

Yes, except that I'd use Y and LM, not the full strength M.  As long as you
use QTR, it doesn't matter which ink position you use for the inks.


If so, who's Magenta and Yellow inks would
> you recommend from a longevity standpoint?
>

Epson.



>
> Wouldn¹t having the color inks in separate stations lead to some of the
> same
> visual defects seen when printing monochrome images with OEM color inks?
>

The issue is how much color you use relative to carbon.  Whether they are
mixed together probably makes no difference.

With respect to the total ratio of carbon to color, the OEM setups use
color inks in their neutral gray to cool the carbon, then you'd be using
more color to warm it back up.  So, the bottom line is that if you start
with carbon to get to a warm, you'll be using less color inks and thus have
less of the issues that relate to them.



>
> If you were going to experiment with such a system, what numbers would you
> start with for the two colors, ballpark?
>

Start by calling the color inks "toners" in QTR.  Then you'll notice that
the density number (maybe start with 30) controls where the peak is in the
curve.  The load determines the amount of ink. The loads for toners can be
very low, but I've never gone the direction you're going.  Once you get
close with QTR's toner curves, you might want to take them manual via the
Point List.  (I'm talking Curve Creator.  I'm on Windows, so if you're Mac
it could be different.)



> ... It also occurs to me that mixing color inks in with carbon
> inks would get very wasteful and tedious as I try to blend just what I
> want. ...
>

Yes.  Software (changing a profile) is much more flexible and efficient
than mixing inks.


> ...
> Would I be able to use HP's magenta and yellow inks alongside MIS's K and
> PK
> dilutions without blowing up my printhead?
>

Yes, but when I looked at the best color ink fade matches, Epson did a bit
better.  That was with LM and LC, however.  The HP neutral did extremely
well, but I doubt they use the same color inks there that they use in the C
and M positions.  You might want to check http://www.aardenburg-imaging.com/ .
 I looked at the pure color fade values.  I can't say for sure that those
numbers actually tell us what you're asking, cut it seemed like they
should.  So, see what the ratings are for the M and Y at, for example, 100
Mlux-hrs on papers that are similar to what you'd be using.


Also, would magenta or light magenta be better? ...
>

I think LM would be better.  The full M dots will show in the highlights.
 What you could do to hedge your bet is buy M and dilute it with generic
base (1 part M to 2 parts base).  Then if it's not enough you can start
increasing it's concentration until you get what you want.  I'd be
surprised if LM isn't good enough, however.



> ... Could one mix magenta and yellow in a single channel, ...
>

The early MIS "toners" were somewhat similar to that approach, and they had
separation issues in wide format printers.  I would not mix different
pigments.


>
> 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.
>
> So I could mix MIS K4 magenta and yellow in the same cartridge and use that
> along with a B&W ink set?
>

Note that I said they worked well in desktop printers.  If you are in a
wide format, I do not recommend it.



> (I read what you are saying to mean that all of the K4 inks can
> theoretically be mixed together except K, because PK, LK, LLK, M, LM, C, LC
> and Y are all glossy inks. Would this also be true of the same inks from
> Epson and HP?)
>

I don't know because I have not done it.  They are probably like the MIS
pigments in their ability to me mixed.  That is, they are probably not
incompatible, but they are also not made to be mixed together.  I would
expect them to have the same separation issues we had with the MIS pigments
(in wide format printers).

>
>
> I've been able to make good cross-overs from about 50%
> to 20% on the dilution steps.
>
> You lost me at that sentence. Cross-over?
>

In the profile when you go from a light ink to a darker ink, that
transition is called a "cross-over" (at least that is what I call them).
 You don't want them to be obvious -- or even visible -- in the print.



>
>
> 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.
>

I meant "MK" there to mean 100% Eboni MK.  The 100% Eboni MK - 30% Eboni MK
(Eb6-C) - 9% Eboni MK (Eb6-LC) prints darker on matte paper than PK - LK
(30% PK) - LLK (9% PK).

(Note that not all LKs are 30% PK.   With, for example, MIS inks, the LK
was set initially with what is now closest to MP-PK, which is a higher load
(more carbon) ink than K4-PK.  However, the LK stayed the same in both
inksets.)

Hope this helps.

Paul
www.PaulRoark.com


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