Provided is a coating system allowing on-demand preparation and coating of an ink. The coating system (10) includes an ingredient ink supply portion (20), a first pipe (90a), a stirring tank (50) including an ink stirring mechanism (52), a supply regulator portion (30) regulating the respective amounts of ingredient inks supplied to the stirring tank, a controller portion (70) connected to the supply regulator portion through an electric telecommunication line (80), determining a mixing ratio of the ingredient inks, and controlling operation of the supply regulator portion based on the mixing ratio, and a coating device (100) including an ink transport portion (120) connected to the stirring tank and including an ink discharge portion (130).