The two machines by the window print in colour and cost four times as much per page. They are not faster. People queue for them because they are nearest the door. A job sent from a laptop stays on the server for two hours and then disappears. Nothing is printed until you tap your card at the machine, so sending the same file three times produces three copies when you finally tap. If a machine jams, take the paper out of the tray and close it again before you report the fault. Most of what is reported as a jam is a tray that somebody has refilled past the line marked inside it.