Abstract: An arrangement for sorting cops in which the latter are provided with premarked spintubes and are guided past a detection system which registers the presence or absence of detection rings on the premarked spintubes in the form of signals. Cops which do not satisfy a required pattern of marks, are rejected. The spintubes are provided with detection rings of a material which is different from that of the tube itself. The detection rings may also be of a different material thickness than the remainder of the spintube. The detection rings, moreover, may be made of metal, and a magnetic field or a high-frequency signal may be used in conjunction with the detection system. The metal may be in the form of iron, copper or aluminum.