The 500-year old Buddhist text Pragyanparamita, illuminated with gold and silver writing, is a marvellous sight even today as the passage of time has not affected either the paper or the text.
The process of preparing these gold and silver inks is a closely guarded secret that is handed down from father to son; in fact the technique of preparing the gold powder tablet (cholun) – one of the critical ingredients – is also a closely guarded secret. It is said that the original formula was brought to Nepal in secret from Tibet. This gold powder tablet is more expensive than its equivalent weight in gold. Both gold and silver powder are used to write on black (or dark) neel patra paper.
PROCESS & TECHNIQUE
Fish shell (nyati) or the head bone of fish (sankha) is boiled in water and its extract transferred into a small vessel. The gold tablet is rubbed into the vessel so that it mixes completely with the fish shell extract to produce the gold ink. The addition of borax or glue adds gloss to the letters that are penned with this ink. As the oxygen in the atmosphere has practically no reaction with the ingredients, the letters keep their lustre through decades and centuries. The process for preparing silver ink is similar