om which abstract features are extracted with image processing. The output of the system is the state of printing pressure, which is divided into 3 states: EXCESSIVE PRESSURE (EP), GOOD PRESSURE (GP), and LOW PRESSURE (LP). Based on the abstract features, the state is estimated with fuzzy membership functions. The shapes of membership functions are determined based on the sampled glasses obtained in actual LCD production line. The experiments are performed with the 2000 glasses that are also printed with actual printing machines, of which the result is compared with that of skilled engineers. It is shown that the proposed system outperforms the quality of skilled engineers. The developed system is installed in actual production line, and it is expected to increase the product quality and production speed, as well as to cut off production costs.