U of S | Mailing List Archive | alt-photo-process-l | Re: oil print color media

Re: oil print color media



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.

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'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.

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 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
>
> ------------------------------------
> www.thijs-foto.com
> ------------------------------------

-- 
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