Berg markets a gold toning kit with a Part A solution of gold chloride (I
think it is approximately .25 percent in strength), and a Part B
thiocyanate solution.
This is a good choice if chemistry is hard to find in your area.
One POP formula you might try is:
Sodium Thiocyanate ........... 15-20 g
1% Gold Chloride Solution ..... 60-80 mL
water to make ................. 1 L
Remember to wash the print after exposure approximately 10-15 minutes until
the unexposed excess silver chloride is removed. Then tone until desired
print colour is reached. Then fix, hypoclear, wash etc.
I have used the following gold formula on albumen prints but I haven't used
it with POP paper. (This toner does not keep well and should be made up
just before use)
Borax ........................ 10g
1% Gold Chloride Solution .....40 mL
water to make ................. 1 L