[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: bubbles in gelatin

At 22:01 10.10.00 -0400, you wrote:
>
>
>On Tue, 10 Oct 2000, Sandy King wrote:
>
>> I size paper for carbon by brushing on a 2-3% gelatin solution (with 
>> glyoxal added) with a foam rubber brush about 3 inches in width. 
>> First I soak the paper, then place it on a flat surface and squeegee 
>> it out. Then, I blot the face with a clean towel to get off all of 
>> the excess water. To coat I use about 100ml of the gelatin solution 
>> per sheet of watercolor paper, 22x30" size. When the gelatin sets you 
>> can dry it on a rack or hang to dry, as you prefer. I often use 
>> alcohol to get rid of the bubbles, but more than you, as much as 8 
>> ounces per liter of solution.
>> 
>> This method is much less messy than either of the methods you 
>> describe. In fact, there is virtually no mess at all.
>
>What do you "squeegee out" with?  On what paper?  It doesn't rough up the
>surface? My squeegeeing has not (yet) been satisfactory.
>  
>Meanwhile, I haven't tested it as well as I meant to -- tests left
>midstream last May need to be started again -- but my experience so far is
>that gelatin brushed onto the top doesn't give as good a size for
>multiple-coat gum as when paper is immersed in the gelatin, which
>permeates it more throroughly. For carbon, I gather you only do one
>transfer, but a gum print can have 5 or 6 or more coats -- sometimes with
>long soak times. After a couple it usually needs resizing, but gelatin put
>ON TOP OF existing color is usually (IME) yucky, makes it look hazy and/or
>greasy. I also suspect that another gelatining & hardening will shrink the
>paper more if anything can & give more register problems.
>
>Also, I find, not all, but many papers will curl if coated only on one
>side.
>
>I'm curious about the glyoxal in the gelatin, however -- that was also in
>the unfinished test series -- glyoxal *in* the gelatin vs.separate coat. I
>got down to those unfinished tests in the alleuvial layer in studio a few
>days ago & found, to my *astonishment,* that the test labelled "glyoxal in
>gelatin" was discolored, the edges where there was a build-up of gelatin
>somewhat carelessly applied apparently, not visible at the time, but now
>VERY discolored.  The "glyoxal separate coat" sheet showed no discoloring.
>
>I soaked the discolored piece in water 24 hours... some lightening in
>part of it but most stayed the same. That was Photographer's Formularly
>gelatin (basic subject of the tests) -- would all have same reaction?  On
>every paper? Who can say?
>
>As Mae West explained, so many tests, so little time... All things
>considered, I see no way to avoid the gelatin soak (& the 3 litres of
>gelatin I mixed last night were NOT enough) but would sure like better
>anti-bubble aid than alcohol.  I think there's one out there...
>
>Judy
>
>

Well, I hardly dare jumping into this discussion between long-time experts,
but this is still an experience: I have found sizing with a foam applicator
on paper soaked in hot water and blotted unproblematic, even without
alcohol. I coat, let the gelatine (2 1/2 - 3 %) set for a few minutes, and
then coat again. After drying, glyoxal with foam applicator. Done on
Fabriano 5.
With my casein prints at least, I have so far found no difference to paper
soaked in gelatine.

Lukas