Ferric Chloride substitute. Fine etch crystal are a superior etchant than the standard ferric chloride pellets. Sodiumpersulphate is much cleaner than ferric chloride, the solution will last 3- 4 weeks although life can be extended by adding a little more etchant powder. Pour crystals into a suitable container and add 2 litres of hot tap water (50°C) Mix until all the crystals have dissolved. For best results use at 45°C.
1.1Kg Clear Fine Etch Crystals, makes 5lt