A flexographic printing system uses a flexographic printing plate to produce printed patterns on a substrate. An ink recirculation system is used to reduce variability in system performance resulting from ink viscosity changes. A recirculation pump moves ink through an ink recirculation line connected to an ink reservoir. A metering pump adds a controlled flow rate of solvent from a solvent replenishment chamber into the ink recirculation line, thereby providing replenished ink which is returned to the ink reservoir. A control system is used to control the flow rate of solvent provided by the metering pump responsive to feature characteristics determined by analyzing a captured image of the printed pattern.