Chemical treatment procedure for removing coloured stains from documents of value consists of steeping in solvent followed by washing with bleach

摘要

The procedure for treating documents, banknotes or cheques that have been accidentally stained with a colouring matter or ink, consists of first steeping them for some hours in a solvent, preferably dimethyl formamide, followed by washing with a bleaching agent such as permanganate, bleach, oxygenated water, a strong mineral acid or reducing agent such as sodium bisulphite.