There are a few more chemicals which was used to gum. Include the
sugar for example.
But as I know the salicylic acid is not a poison: under 8 g/day it is
a medical of rheumatism... (Do not eat too much gum solution because
it is necessary to the print...)
Details. For solution wich is usually 40g gum to 100ml water:
1 drop of 10% solution of phenol
(J.M. Eder: Das Pigmentverfahren..1926. p.257)
20 g sugar (J. Gaedicke: Das Gummidruck. 1906. p.20)
half cube of sugar :-) or 5 drop of NH4OH (ammonium-hidroxyde)
(G. Szakal: Gyakorlati fenykepezes. 1919. p.200)
4-5 drop of phenol or 1 crystal of thymol
(A. Grabowsky: Muveszi fenykepezes. 1917. p.118)
a few drop of formaldehyde
(B. Lavedrine: La Conservation des Photographies 1990. p.135)
etc, etc. (Continue.) (If necessary.)
Balint Flesch