Ink evaluation method, ink, and ink jet unit

摘要

An ink evaluation method of the present invention comprises: a first step of making a given amount of solution pass through a filter and measuring time for the solution to pass through the filter; a second measurement step of making pass through the filter the ink having a solid material dispersed in a solvent and having the same viscosity and the same amount as those of the solution, and measuring the time for the ink to pass through the filter (filter passing time); a calculation step of calculating a ratio of the filter passing times between the solution and the ink; and a determination step of determining whether the ink discharging stability index is high or not based on the measured ratio. Thus, since the ink having a high spraying stability index can be easily determined, ones having the high spraying stability index out of plural types of ink may be selected.