In a known method for producing a tube of quartz glass by elongating a hollow cylinder of quartz glass 6b having an outer diameter AD, said cylinder is continuously supplied to a heating zone with a vertically oriented heating tube having an inner diameter d, with the proviso that the diameter ratio dAD is set to a value ranging from 1. The imaging system includes one or more laser sources that are configured to produce one or more light beams. A set of usage facts associated with the identified object is identified. Preferably, the Knoop hardness of the ionic solid is at most about 20, and the elongation ratio of the ionic solid is at least 10% at a temperature of 120-180 C. The plastics material is preferably easily machinable, and tough and durable, and may be selected from known plastics materials of this type such as nylon, polyethylene terephthalate, and the like.