Re: oil print color media
On 22 jan 2007, at 23:29, Gordon J. Holtslander wrote:
Hi:
Henk. Thanks for the info on small volumes of litho ink
Graphic chemical & arts (GC&A) appears to carry some:
http://www.graphicchemical.com/shopdisplayproducts.asp?id=294&cat=Litho%2DSketch
One of the reasons I am trying oil paint is that it is available locally.
Though GC&A will ship parcel post which makes ordering from them pretty
reaonable.
The other reason was that I didn't want to buy a lot of ink only to discover I
wasn't able to do what I want.
What is the trick of spraying water on a fresh inked matrix, and
rolling quickly with a clean foam roller? Would that pull some of the ink
off?
If you start inking, and just want to see a quick result of detail et al, just spray some water over it, and rolling with a dry foam roller will take off the ink from the highlights and intensify on the midtones and shadows.
If the ink is very 'stiff' on the matrix, you even could do it in water and 'rub' with a foam roller; it is astonishing what you can do with a fresh inked matrix.
succes,
Henk
Gord
On Monday 22 January 2007 12:51 pm, henk thijs wrote:
On 22 jan 2007, at 18:33, Gordon J. Holtslander wrote:
Hi:
I'm using Winton oil colors. Its a relatvely inexpensive brand -
didn't want
to spend a lot of money til I had some idea of whether or not the
technique
would work.
Just wondering about the reason you go for the oil paint; there are
also litho paint in tubes (Faust , Charbonnel), still not stiff enough,
but easier to reach the right stiffnes. With oil paint i often had the
impression that addetives where used , which didn't work for me.
I often use pure pigment to stiffen and to change the color.
I use a spirit sensitizer - 6 % ammonium dichromate mixed with 2 parts
of
isopropyl alchohol. I really want to avoid tray sensitizing - I don't
want
to work with large volumes of dicrhromate if I don't have to.
Do you brush on your pottasium dichromate or soak your sheets in a
tray of
dicrhromate?
I coat twice with a foam brush of about 8 to 10 cm . If you do it in a
rush with a lot of pot.dichr. you have a nice result without streaks.
It is much more difficult to avoid streaks with the gelatine.
I've been trying different techniques for laying down the gelatin. I
had
started with coating 3 layers of ~ 5% gelatin with a brush. I'm
trying to
come up with a way of getting a thick coat in one step. I will try
higher
concentrations of gelatin. The last print I inked I found I was not
able to
get the media to "differentiate" the finer details in mid tones - it
was able
to differentiate between the shadows and highlights. How much impact
does
the concentration of gelatin have on inking the matrix? Was going to
try 10%
gelatin the next time.
I would not go for more than 10 % ; if you work in different steps,
with repeatedly soaking the -partly- inked matrix you are risking
gelatine coming off the paper.
Last time I tried coating with a threaded rod - worked OK - but I
worked witth
a large sheet of paper 22" by 25". I discovered my countertop is
uneven
enough to make it nearly impossible to get an even coat with a
threaded rod.
In the past I would coat smaller pieces of paper and put a sheet of
glass
underneath - didn't have any glass big enough for a full sheet. Wiill
try
putting something under the paper that gives a little bit to
compensate for
the uneven surface of my counter top. Was going to try a large foam
roller
and see if it can put down a thick layer. Was also trying to come up
with a
way of making a comb that would spread a thick layer - may try trowels
for
putting down flooring adhesive - but I think they would damage the
paper.
My largest neg is about 47x57 cm (the max for the lightbox) and coating
the gelatine (also for gum) is putting a sheet of glas on top of a
bin filled with warm water, on top the several pieces of paper, and
coat with a broad foam-brush.
And yes , details aren't the real thing with oil-printing.
You know the trick of spraying water on a fresh inked matrix, and
rolling quickly with a clean foam roller?
succes,
Henk
My negatives are large format pinhole negatives on film. - a bit
contrasty -
but not outrageous.
On Monday 22 January 2007 10:34 am, henk thijs wrote:
Gordon,
thanks for the info; doing oil-printing for several years now, and
also
using pigment with standoil, oil paint etc. just some
remarks/questions:
- in my experience there are 'good' & 'bad' brands for oil-paint,
which
do you use ?
- what about the gelatine coating; in the literature i found 6 percent
gel several coats; for me the best was 3 coats of 10%. What is your
experience?
-what about the dichromate? I use a 10 percent pot. dichromate,
coating
twice.
- i use paper negs, very contrasty, like the one for cyanotypes.
Cheers,
Henk
On 22 jan 2007, at 6:08, Gordon J. Holtslander wrote:
Hi:
Just a FYI in case other people are working with oil prints. I've
been
trying to find a media to make "constructed color images" using oil
printing. An oil print is similar to a bromoil print. It relies on
using a oily media that is repelled by water.
I have been experimenting with a variety of media to use for doing
color
oil prints. I've been avoiding using litho inks - I think using
smaller
volumes with a wider range of pigments is more manageble.
Most references I've read state thats its possible to make your own
oil
print media using tube of oil paint with magnesium carbonate and or
wax
added to make the paint stiff enough to use with oil printing.
Others
state its possible to make an oil media by mixing stand oil with
pigment. I was not able to produce an oil media "stiff" enough to
use
with the oil print matrixes I produced with either of these methods.
The
media was not sufficiently repelled by water to be effective.
I have found a technique that looks promising. I tried using litho
varnish, mixed with tube oil colors. This produces an oil media that
is
sufficiently stiff enough to work on the oil print matrixes I make.
Litho varnish is used in lithography to stiffen a litho ink. Litho
varnish is produced in a range of numbers - the higher the number the
stiffer the varnish. I'm using a number 8 varnish - from American
Chemical & Ink.
This appears to produce an oil media stiff enough for oil printing .
Now all I have to do is make better oil matrixes.
Gord Holtslander
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www.thijs-foto.com
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--
Gordon J. Holtslander Dept. of Biology
gordon.holtslander@usask.ca University of Saskatchewan
Tel 306 966-4433 112 Science Place
Fax 306 966-4462 Saskatoon SK., CANADA
homepage.usask.ca~gjh289 S7N 5E2
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www.thijs-foto.com
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--
Gordon J. Holtslander Dept. of Biology
gordon.holtslander@usask.ca University of Saskatchewan
Tel 306 966-4433 112 Science Place
Fax 306 966-4462 Saskatoon SK., CANADA
homepage.usask.ca~gjh289 S7N 5E2
------------------------------------
www.thijs-foto.com
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