 As the technology matured, most large printer installations were drum printers, a type of impact printer which could print an entire line of text at once through the use of a high speed rotary printing drum.It was thought that in the event of a severe jam, the friction of paper against the drum could ignite either the paper itself, or, in a dirty machine, the accumulated paper and ink dust in the mechanism.Whether this ever happened is not known; there are no reports of friction-related printer fires.