(Source : Working with Alternative Processes - Peter Marshall)
Stock sol.
1 g of gold chloride in 15 ml water
- OR - 1 g sodium tetrachloroaurate in 13 ml water + 2 ml 10% hydrochloric acid.
- OR - 1 g hydrogen tetrachloroaurate in 15 ml water + 0.27 g anhyrous sodium carbonate.
Use : Add 0.5-1 ml of stock solution to 1 litre of water and add pinch of borax or sodium hydrogen carbonate.
Make up just before use. Treat ~ 2-6 mins., then wash for 10 mins. Salt bath can be used as a toner stop bath before washing.
For pink/red tones, first sepia tone the print.