Thanks for your reply.
I have not replied earlier as I have been involved in Sussex gum platinum
workshop where we produces some exciting g/p prints and we are nearly at the end
of the gravure workshop in Kentish Town.
>They no longer do alt processes at Gloucester or Cheltenham for that
>matter.
That is a pity because the college has a good reputation. Maybe we could
persuade them to include one or two days a year.
>I belong to an amateur group of monochrome enthusiasts called
>'The Cotswold Monochrome Fine Print Group', and I have managed to get
>one or two members interested in Bromoil, Carbon printing, and Gum
>bichromate. I should add that we are all beginners where alt processes
>are concerned.
Sounds as if you need to think of a change in title, perhaps leaving out the
word ' monochrome'.
>I have ordered a small quantity of the deionised ossein 260 bloom,but
>meanwhile I have been trying out a gelatin scrounged from the laboratory
>of a friend. This gelatin is of French manufacture (Duche'), is a fine
>powder and is labelled '800B', and that is all the information I have.
I only use the Croda product because it works for gum, oil, platinum, salt,
cyanotype etc. etc. I do not know anything about the Duche product but if you
find it works I am sure we will all be interested to know.
As to sensitising of oil prints , I have had consisitently good results using a
hake brush. I use a 4 % sensitiser for potassium and a 3 % sensitiser for the
ammonium dichromate and I have never found it necessary to include sulphuric
acid in the mix.
As to PVA in gum prints I find it works perfectly for single coats but it seems
to hardsen so fast for the second coat that it is imprictical to use it for
multi-colour gums. maybe if one were to reduce the solution for the second coat
to 1 5 for the second coat it would work.
I have not tried immersing the coating in the dichromate, simply because
of the problem of handling large quantities of ammonium or potassium
dichromate solutions in a confined space. I would, however, be grateful
for the groups views on the advantages of immersion over brush or pad
application.
Gloy, which I discovered in Gloucester, which works as well as gum arabic, is a
variation on PVA.
Nice to hear from you.
Terry
Alex.
Alex Nanson
Gloucester UK