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
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