Known methods and devices for overlap-welding of printing by means of ultrasonics have been developed further to enable problem-free use, particularly with wire printers also having thin wires, and to enable welding of multi-color ribbons. The invention also permits more durable components. In the method according to the invention, the printing ribbon to be joined is retained in a non-overlapping fashion on movable plates, preferably by means of a vacuum, and is severed by a cutter, preferably by means of an ultrasonic sonotrode and cutting anvil, and is then moved so that the ribbon ends are in overlapping position, and then welded, preferably with a structured part of a sonotrode on a wielding anvil which is likewise structured. A device according to the invention has two plates with ribbon-retaining means, a cutter, and a joiner, such as a welder, for joining the two ribbons ends. The plates are movable to at least two positions suitable respectively for the cutting and joining functions of the machine. A device for accomplishing the method may utilize standardized components which are usual in trade, is accordingly disturbance-free and may be produced economically and guarantees high production rates.