A medium, system, and method are disclosed for a common data storage medium depression depth. An optical data storage medium comprises a plurality of spacer layers and data surfaces. A wavelength for a radiation beam such as the emission of a laser diode is identified. The index of refraction for a first spacer layer or substrate is also identified. The substrate is configured to transmit the radiation beam. The index of refraction of a second spacer layer that is configured to transmit the radiation beam is also identified. A depression depth for a plurality of pits for ROM media, or sector headers for recordable media, or grooves for recordable media on each data surface is substantially equal to the radiation beam wavelength divided by four times the average of the indexes of refraction of each spacer layer. In one embodiment, the average is an arithmetic mean of the indexes of refraction. In an alternate embodiment, the average is a harmonic mean of the indexes of refraction. The average may also be a geometric mean of indexes of refraction.