Katharine Thayer wrote:
>
>This is what I was trying to say to Sandy a while back and couldn't make
>myself understood, in the context of percent solution of gum. I notice
>in one of the articles I read today that as far back as 1930,
>researchers knew that percent solution of gelatin is not a useful
>measure and that "in order to obtain results truly comparable with each
>other the estimations should be carried out on solutions containing
>equal concentrations of nitrogen." (Galinsky, 1930).
I don't find any of of this relevant to the issue of making carbon
prints. I have used over the years more than a dozen different
gelatins from many suppliers,including both porcine and ossein
sources, and they all gave good results in carbon printing. Whether
the concentration of nitrogen makes any difference I don't know but I
would not put stock in any reports that show that it does unless the
tests were actually made in conjunction with making real carbon
prints.
As far as I have been able to determine the major factor in
determining how a given gelatin will work in carbon printing is its
Bloom, yet more than one person has insisted to me that this should
not matter at all.
Sandy
Received on Fri May 21 08:58:49 2004
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