recording surface
Refers to the physical surface of a medium (CD, tape, disk, etc.) where data is recorded. Technical term used in media and electronics contexts.
If the recording surface of a CD gets scratched, it may become unplayable.
The recording surface of this tape has deteriorated, and the sound is muffled.
Compound of 記録 (record) and 面 (surface). The exact historical derivation is uncertain, but the word follows a common pattern for technical terms.