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

On Thu, 19 Jan 2006, Gordon J. Holtslander wrote:

> The liquitex is labelled:
>
> Liquitex Acrylic Gesso Transparent
> has the number 7604 on the bottle

Thanks... good to know. As for the name, however, I suppose there's no law
you couldn't call it Acrylic Liquid Breakfast, but like I said,
traditional "gesso" (including Liquitex Gesso, which I use, BTW) contains
a whiting product. Linen canvas (eg Belgian linen) is tan or brown &
comes raw (or at least used to) so the artist has to add something to make
it white & smooth out the weave, then an isolating layer to keep oil in
the paint off the cloth (which it would rot &/or yellow). Cotton canvas
tended to come already coated, but if not, the painter treats it
similarly.

However, I doubt gesso ever contained titanium -- too expensive for the
covering process, among other disabilities. (On the other hand, even dorks
aren't "dorks" any more, so who knows?)

Judy

>
> 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 Sat Jan 21 14:58:22 2006