“Commercially available India Ink has been used by endoscopists to mark or tattoo lesions for subsequent surgery or endoscopy since 1975. A new endoscopic marker has been developed. It is sterile and pre-diluted and is devoid of clinical side effects. It should replace commercial India Ink which contains shellac, phenol, ammonia, and other unknown and proprietary chemicals.”
Fiedler L.M., Waye J.D., Harpaz N., Janowitz D. The Disappearance of India Ink. Gastrointest Endosc. 2000 Apr;51:4:2 AB272.