Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer {comprising a magnetic layer on both sides covered with non-magnetic material}
Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer {comprising a magnetic layer on both sides covered with non-magnetic material}