Re: oil print color media
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? 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 > >> > >> ------------------------------------ > >> 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 > > ------------------------------------ > 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
|