A printing unit of a printing machine is supported by a pair of spaced side frames that are disposed opposite to each other. The printing unit includes at least one printing machine and at least one ink unit. The printing machine is formed by a plurality of printing cylinders. Each of the spaced side frames include a longitudinal crossbar that runs in the direction of transfer of a print substrate traveling through the printing unit. The two longitudinal crossbars form the boundaries of a foot space of the printing unit at two parallel sides. A plurality of pipelines are disposed in the foot space between the two longitudinal crossbars. These pipelines supply flowable media to the printing unit, which flowable media can be either liquid or gaseous. At least one of the pipelines is connected to a user of one of the supplied flowable media in the printing unit or to at least one source of the flowable media. The printing machine can utilize a plurality of printing units.