U of S | Mailing List Archive | alt-photo-process-l | Re: Gum Calibration 2 (How to read color samples?)

Re: Gum Calibration 2 (How to read color samples?)



Hi Loris,

Maybe but,

All my pigments are diluted 15ml to 150ml paint to gum. Any less
and they get very wishy washy (insipid).

David


On Oct 24 2008, Loris Medici wrote:

David, could it be that the pigment concentration is too much?

Greatly unlikely at those concentrations, IMO. But I have to agree
with David; that's what I've seen again and again, that often when
people calibrate their layers individually they then find to their
surprise that such calibration of the separate layers doesn't sum to
a perfect tricolor print, from any number of standpoints.

The problem is that when you approach the layers as separate
entities, there is a natural tendency to calibrate and print each
layer so as to make a good standalone print, which is the wrong way
to approach tricolor. A tricolor print isn't the sum of three
standalone layers, but a three-dimensional object made of three
layers, any of which wouldn't necessarily look like much printed by
itself, but overlaid they create the tonal and color totality as a
result of how they add to and interact with each other. All
adjustments of layers have to be done considering the whole 3-
dimensional print, not just one layer. My 2cents.

kt




On Oct 24, 2008, at 12:17 PM, davidhatton@totalise.co.uk wrote:


Hi Loris,

Maybe but,

All my pigments are diluted 15ml to 150ml paint to gum. Any less
and they get very wishy washy (insipid).

David


On Oct 24 2008, Loris Medici wrote:

David, could it be that the pigment concentration is too much? I
think the
problem lays right there. In an article by Sam Wang it was written
that he
mixes his color to a saturation and luminosity close to the test
patches
found in color newspaper (usually printed somewhere in the bottom
or in
the middle of two pages). And I remember Katharine writing
something about
this too...

Regards,
Loris.

P.S. Going to mix a new batch of gum (from powder) that will be
used to
make stock solutions...

I will start with:

1+3 PY151 (15ml paint giving total 60ml stock)
1+5 PV19 Rose (15ml paint -> 90ml stock)
1+7 PB15:3 (15ml paint -> 120ml stock)

and dilute more as necessary.


24 Ekim 2008, Cuma, 9:06 pm tarihinde, davidhatton@totalise.co.uk
yazmış:
>
>
> Hi Loris,
> Your idea sounds good, however it doesn't fit with the instructions
> which come with the product and I haven't tried it. Give it a whirl
> and let us know how it goes. The problem I have with both these
pieces of
> software is that, yes you get a good curve for each individual
colour and
> yes you will get a fully tonal print from each colour, but when
you lay
> one coat upon another all bets are off. The resulting images
(IMO) are
> far too dark/dense.
> Good Luck though
> David H