An apparatus configured to characterize a magnetic recording tape of a tape cartridge, according to one embodiment, includes a magnetic head having servo readers of known pitch, a drive mechanism for passing a magnetic recording tape over the magnetic head, and a controller electrically coupled to the magnetic head. The controller is configured to measure, using signals from the magnetic head, a servo band difference at various locations along a length of the magnetic recording tape of a tape cartridge. The controller is also configured to store the servo band difference measurements and/or derivatives thereof in association with the tape cartridge.