Digital BW, The Print

----- Original Message -----
From: "Roy Harrington" <roy@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Monday, March 10, 2003 8:55 AM
Subject: [Digital BW] Ink Set Ideas and Questions (7500)


>
> All these new inks and ink sets have been very interesting.
> I'm finally going to take possession of a 7500 this week, so
> I have to order some inks.  I've liked the VM-Sepia inks for
> my 1160 and just getting those for the 7500 is certainly an
> easy solution.
>
> But, with 6 inks now and my QuadTone workflow I've got
> more control and options than an RGB workflow.
>
> With the CMYK workflow I've gotten the best dMax by using
> 100% black ink plus 100% cyan (dark gray) -- i.e. I can easily
> specify 200% ink usage for dMax.   So my idea is to try for
> using 2 inks that are black to get 200% pure black.  So the
> question is what ink to give up.

Interesting message Roy.

There are however few inkjet coatings that allow 200 % ink
without losing detail. Even with a linearised 9000 I usually get
no further than 175 % on Hahnemuhle coatings. Wasatch SoftRip,
the primary RGB colours mixed from CM MY YC. There's another
reason not to go any further, with pigment inks you will not gain
extra black nor in the case of colours extra gamut. The pigments
are just too opaque, for colour where no light gets through to
the substrate
so you do not get filtered light reflected, for black where no
light is lost in the depth of a dye pool it is reflected from the
surface of the pigment particles. Paul wrote a message just
before yours where he compared a double printed black with a
single one and not much difference between them. At the colorsync
list there was a short thread on the gamut gain with pigment inks
and where the ink limits should be set before making the profile
as for example a 100% cyan + 100% magenta doesn't deliver more
gamut than a slightly lower percentages.

There's a difference between Paul's double printing and printing
200 % ink on the paper in one go. Inkbleed in the depth and width
of the coating is increased with the last compared to the first
where there's drying in between. The density will probably be
higher with the 200% ink in one go.

There is however a good reason to add some dark grey (and in my
case composite grey) to even the darkest black. With the 9000 (
and it will not be much different with the other models of that
generation) you often get white lines in the black with pigment
inks. That is gone with the addition of a low percentage of grey
ink up to 000 RGB. Under Colour Addition so to speak. Before you
start with less grey inks I would recommend to print some samples
of black with details and check what is gained and what is lost
in terms of density, smoothness, detail. For smoothness it may
even be better to add small percentages of two greys into the
black. If you really go for two blacks then I think you will not
use 200% at all. Consider a gloss black and a matt black then,
there are other advantages than density with that set.

Ernst