The strength of the magnetic field that remains in a tape or magnetic particle after it is:
1. exposed to a strong, external magnetic field and;
2. the external field is removed.
The property of a tape that determines its ability to record and store a magnetic signal. Mr is the common abbreviation for magnetic remanence. Magnetic remanence (Mr) and magnetic retentivity (Br) both refer to the ability of the tape to retain a magnetic field; however, the latter is expressed in units of magnetic flux density.