Very few early programs were saved on tape. When a tape is exposed to extremes of temperature and humidity, the layers expand and contract. As magnetic tape ages, the oxide particles whose magnetic properties hold the image may begin to separate from the base. Age may also adversely affect the adhesive binder, causing the tape to become sticky - thus making playback impossible. Improper storage creates additional problems.
Excessive humidity can cause microorganisms to flourish.
Tapes not properly wound may have uneven tension resulting in tape stretch and warpage. Food and coffee are frequently spilled on tapes in control rooms. Even when magnetic tape is kept under the most ideal conditions, if a working machine is not available, the information stored will be irretrievable. Recording machines rapidly become obsolete and unavailable. Those machines that still exist are often poorly maintained and seldom able to give optimal playback.