A magnetic strip is a magnetizable strip made up of iron-based microparticles. Magnetic strips are usually located on the back of EC, credit or check cards and are used to store information. The information on the magnetic stripe is written by an electromagnetic read and write head by magnetizing the magnetic microparticles.

Magneto-optical sensor systems, such as the computer-aided cmos-magview or the mobile hand-held device magview, are ideally suited to quickly and reliably examine the quality of the magnetic structures on the magnetic stripe. The information can be made visible within seconds and incorrect or possibly manipulated information can be identified.