The printing cylinder such as a rubber blanket cylinder of a web fed offset printing machine is provided. The printing cylinder includes a rotatable clamping mechanism in a clamping channel. A side of the clamping channel is configured so as to be movable such that the clamping channel can be opened by turning the clamping mechanism. When the clamping channel is open, the ends of the rubber blanket can be inserted. The clamping channel can then be closed by turning the clamping mechanism in the opposite direction such that the ends of the rubber blanket adjoin one another.