Re: Gelatin-polymer blend (was Re: Gesso sizing)

From: Gordon J. Holtslander ^lt;holtsg@duke.usask.ca>
Date: 01/19/06-10:35:48 PM Z
Message-id: <Pine.OSF.4.53.0601192217110.89968@duke.usask.ca>

The liquitex is labelled:

Liquitex Acrylic Gesso Transparent
has the number 7604 on the bottle

label states

"Flexible clear acrylic gesso for acrylic oil pastel and more"

The white glue is

Weldbond Universal Adhesive

My foam roller was bought from the local Coop hardware store (my favourite
photo supply store :) )

Its a finishing roller a foam roller about 7 inches long 1 inch diameter
with a very fine nap.

I charge it by pouring the gelatin mix in a narrow tray just larger than
the roller.

I clean these just by rolling rinsing and squeezing out moisture.

I often get fine bubbles from the roller - I will often wipe with a finish
paint "pad" that has the same fine nap as the roller.

I'm not claiming to get spectacular results. Just haven't been happy with
the way I sized in the past - often got crappy sizing. Trying to see if
there are easier quicker better ways to size.

Will try casein (and maybe casien -weldbond) for sizing too.

Gord

On Thu, 19 Jan 2006, Judy Seigel wrote:

>
> On Thu, 19 Jan 2006, Gordon J. Holtslander wrote:
>
> > Liquitex make a clear acrylic gesso - I assume (bad practive) that is has
> > no titanium whitener.
>
> Definitions change over time -- I remember when a "dork" was a jerk,
> which is to say a nudnik, and now it seems it's an expert, geek or techie.
> So I say with some reservations that by definition *traditionally* a gesso
> had to have a whiting substance in it. To quote Mayer: It's made by mixing
> "an inert white pigment such as chalk, whiting or slaked plaster of Paris
> with an aqueous binder such as a solution of glue, gelatin or casein."
>
> I don't think by the way that gesso has titanium -- Mayer has a section on
> "Defects of Gesso panels" which I haven't read for 105 years, but my
> recollection is that they would be some kind of cracking, which presumably
> (better word than "assume," n'est-ce pas?) would be obviated by the
> gelatin.
>
> When I learned to make gesso, 103 years ago, we slaked plaster of Paris...
> and somewhere along the line I was told that *rotten* plaster made the
> best gesso, that is, you slake then keep a year or so til it rots. I made
> some up and worked off it for a long time -- I haven't used the gelatin
> gesso mix for a while (Bernie Boudreau's version is cited in P-F #6),
> because for my printing, plain Knox hardened in glyoxal or formaldehyde
> proved easiest & best. But I still have a couple of inches of the rotten
> plaster in a gallon container.
>
> That's the beauty of rotten plaster -- it keeps !
>
> PS. Gord: Does Liquitex call that clear stuff "gesso", or ...? Is "white
> blue" a misprint for "white glue"... or... ? (Elmers, maybe?) How do you
> clean the foam roller? Any special kind of foam?
>
> TIA,
>
> Judy
>
>
> >
> > I have been playing around with sizing techniques.
> >
> > Did a mix of gelatin (250 ml) and a little (20 ml) white blue, hardened
> > with chrome alum, rolled on with a foam roller. Seemed to give a much
> > smoother/cleaner surface than plain gelatin. But then the gelation coat
> > may simply have been poorly coated.
> >
> > Gord
> >
> > On Thu, 19 Jan 2006, Ryuji Suzuki wrote:
> >
> >
> >> I've tried gesso mix but one objection I had was that the acrylic
> >> gesso is gritty because of matting agents in the mix. Another
> >> objection I found is that the gesso contained titanium white and other
> >> things I would not want to have in my prints unless archivality is
> >> proven in the particular combination. Titanium white is very
> >> photoactive and generates a lot of radical chain reaction in the
> >> material when exposed to UV, and this was the main cause of problems
> >> in early days of RC papers. Photographic industry learned enough and
> >> today's products have good amount of means to prevent the problem, but
> >> I am not sure of gesso in sizing layer.
> >>
> >
> > ---------------------------------------------------------
> > Gordon J. Holtslander Dept. of Biology
> > holtsg@duke.usask.ca 112 Science Place
> > http://duke.usask.ca/~holtsg University of Saskatchewan
> > Tel (306) 966-4433 Saskatoon, Saskatchewan
> > Fax (306) 966-4461 Canada S7N 5E2
> > ---------------------------------------------------------
> >
> >
>

---------------------------------------------------------
Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
---------------------------------------------------------
Received on Thu Jan 19 22:35:53 2006

This archive was generated by hypermail 2.1.8 : 02/14/06-10:55:39 AM Z CST