Re: Oil Printing
Alex Nanson (alec@norlex.demon.co.uk)
Mon, 22 Jul 1996 16:31:47 +0100
In message <960630153408_100561.2417_EHK58-1@CompuServe.COM>, Pollmeier
Klaus <100561.2417@CompuServe.COM> writes
>
>
>Yes, you should use a little chrome alum in the gelatin for oil printing and you
>should even try a small amount of dextrin (potato starch, 10% of the gelatin
>amount) to give the gelatin a certain 'tooth' which makes the ink adhear better.
>
>The chrome alum is esp. required if you want to use the oil print for transfers.
>My favourite formula is:
>
>A
>15% gelatine sol. 160,0 ml
>15% starch sol. (Dextrin) 16,0 ml
>
>B
>6% acetic acid sol. 6,0 ml
>1% chrome alum sol. 8,0 ml
>
>Keep A and B at 60-65 C and slowly add B to A with constant stirring. Take ca.
>40 ml to coat one sheet 50x70 cm. If the gelatin gels in the beaker allready,
>your solution wasn't hot enough. Rewarming is impossible. Beakers and brushes
>are difficult to clean even in hot water after the gelatin has gelled. Let them
>soak in a solution of detergent used for the washing mashine first.
>
>Klaus Pollmeier
>
Klaus,
Thank you for your suggesions. I am particularly interested in the idea
of adding starch to the gelatin in order to impart 'tooth'. I notice
that you state that the starch should be added as a solution. Does this
mean that as the gelatin cools the starch comes out of solution and
forms a dispersion of fine particles within the gelatin layer?
It occurs to me that an alternative to starch, would be one of the fine
silicas or other such fillers that are used to reduce the gloss of
surface coatings.
Alex.
Alex Nanson
Gloucester UK