Inked Fabric Printer Ribbon: Tricresyl Phosphate, Castor Oil and Carbon Black Ink (Neidich, Underwood, US 2,139,092)

Ribbon inks made with plain oils went thin in warm weather and rancid with age, so the ribbon printed unevenly and soon dried out. Neidich replaced half the oil with tricresyl phosphate, which keeps the ink at an even thickness and does not oxidise. Result: a fabric ribbon saturated with a non-drying black ink for typewriters and printers. Source: Neidich, US 2,139,092 (Underwood Elliott Fisher, 1938). Not given: which fibre the ribbon is woven from (he says only an absorbent fabric), how the ink is put on. Picture drawn by Youblob.