A color digital printing system for print firms. Meeting high demand for commercial printing, with high image quality / stable quality / various paper support, it can produce DM / catalog / package / postcard and other prints. Especially the system manages new needs of "multiple / small-lot, short-term, variable (content-specific)" printing unfit for offset printing, helping printers expand services. With downtime minimized, installed two toners of each color enable long operation. Operation guidance LED to clear paper jams quickly supports recovery. A dedicated print server's flexible UI manages jobs efficiently to release users from difficult operations.