Your quetions:
>1). How critical is the type of gelatine or gum used for the dichromated
coat?
It is important. I do not think that the gum plays any part in the process so
leave it out. Use deionised ossein 260 Bloom availble from Croda Colloids in
Cheshire.
>2). Is it necessary to size the paper before applying the dichromated
coat?
No. Build the size into the coating process. One coat at 3% and two at 5% ; dry
between each coat.
>3). Is it OK to apply the dichromate solution by brush or should the
paper be soaked in it?
It is better to put the paper in the solution and agitate gently; the soak
should last three minutes.
>4). How critical is the exposure?
If you get it wrong it won't work. Do a test strip.
>5). Are standard Bromoil inks satisfactory for the oil printing process?
Yes.
When making up the gel add 0.25 g of chrome alum per 100 ml. Take a little of
the water for the gel ( 5 ml ) and make up a solution add it to the solution.
>One further query! Are Bregman register pins or their equivalent
obtainable in the UK?
I use map pins.
I will forward you further information
Terry King
Alex.
Alex Nanson
Gloucester UK