Potash Alum has been extracted from alunite from at least 1500 BC and is the historical mordant called for in traditional dye and marbling instructions. It is not the same as Aluminium Sulphate crystals. Potash alum is not considered harmful under normal circumstances.

We would recommend using 12 - 20% Alum per 100 grams of fibre. 

Our alum is supplied in a 100% Biodegradable resealable pouch as we believe in minimising our carbon footprint as much as we can.