Method of operating a printer

A method of operating a printer having respective stores for a plurality of paper webs to be printed, at least one printer head disposed along a printing path, respective driven in-feed heads between said stores and said path for feeding the respective webs selectively to and along said path and past said printer head, and means downstream of said path for leading said webs away from said path, said method comprising the steps of:

• (a) displacing a first paper web from one of said stores with a first of said in-feed heads along said path and past said head to print successive sheets of said first paper web with a given positioning of an imprint relative to a leading edge of the respective sheets;
• (b) for changeover of said stores to print sheets of a second of said paper webs, separating a last-printed sheet from said first paper web to produce a leading edge of said first paper web at a setpoint position along said path corresponding to said given positioning of said imprint;
• (c) retracting said leading edge of said first paper web from said setpoint position until said leading edge of said web reaches a sensor upstream of said printer head with said first in-feed head and storing in memory by activation of said sensor a displacement difference of said first in-feed head between said setpoint position of said leading edge of said first paper web and a position of said leading edge of said first paper web at said sensor;
• (d) thereafter withdrawing said leading edge of said first paper web further to a predetermined parking position;
• and
• (e) for further printing of said first paper web, advancing said first paper web with said first in-feed head to a desired print position for each sheet thereof corrected based upon the stored displacement difference for said first in-feed head.