The procedure was as follows: firstly, preparing printing ink from the substance Cu2HgI4 and varnish,
secondly, testing on rate of ink flowing, setting time, and color-changeable to temperature dependency at different mixing ratios of 10%, 15%, and 20% by total weight,
including rub resistance, and color density.
The results of experiment showed that the offset printing ink at the ratios of Cu2HgI4 in 10% 15% and20% had color changeable when it was heated at temperature between 34.5 - 70 degrees Celsius, the ink color definitely changed from red to black color. The ink property testing such as the rheological, drying, rub resistance and color density showed that the thermochromic inks mostly had the properties closed to a typical offset lithographic printing ink.printing ink.