Faulty useful units printed on a sheet of useful units are separated from
the acceptable useful units. A first cutting device cuts the sheet into a plurality
of longitudinal strips, each of which contains several of the useful units. A quality
control device detects the faulty useful units prior to a second cutting device
that cuts the strips into individual units. A filtering unit is placed between
the two cutting units and filters out strips with one or more faulty units. Strips
with no faulty units replace the filtered out faulty unit strips. This simplifies
further processing of the strips.
