Machine and method for printing material webs

A machine for printing material webs (4),

• which comprises a station (1, 11, 41) for monitoring the printed material web (4),
• with the station (1, 11, 41) for monitoring the material web (4) comprising a sensor (3, 1.3) for monitoring the web (4) and at least one counter support (2, 12) for guiding the web (4), with at least one counter support (2, 12) being located on the side of the web (4) facing away from the sensor (3, 13),
• characterized in that
• devices are provided with which a pressure difference can be generated and which are installed such that a force results acting upon the web in the direction towards the counter support,
• comprising a first device, arranged at the side of the web facing the sensor, which generates a pressure, with this device comprising pressurized air jets (6, 7), with a first pressurized air jet (6) acting upon the web (4) upstream from the counter support (2, 12) and a second pressurized air jet (7) acting upon the web (4) downstream from the counter support (2, 12),
• and/or a second device, arranged at the side of the web facing away from the sensor, which generates a vacuum, with this second device comprising jets (53) from which air flows can
• be guided out, pressurized and aligned perpendicular to the travel direction (z) of the web (4), with the jets (53) being arranged upstream and downstream from the counter support (2, 12) in the travel direction of the web (4).