Editing Punched tape (section)

== Advantages and limitations ==
[[Acid-free paper]] or Mylar tapes can be read many decades after manufacture, in contrast with magnetic tape that can deteriorate and become unreadable with time. The hole patterns of punched tape can be decoded by eye if necessary, and even editing of a tape is possible by manual cutting and splicing. Unlike magnetic tape, magnetic fields such as produced by electric motors cannot alter the punched data.<ref name="Sinha_1986"/> In cryptography applications, a punched tape used to distribute a key can be rapidly and completely destroyed by burning, preventing the key from falling into the hands of an enemy.

Reliability of paper tape punching operations was a concern, so that for critical applications a new punched tape could be read after punching to verify the correct contents. Rewinding a tape required a takeup reel or other measures to avoid tearing or tangling the tape. {{citation needed|date=January 2016}} In some uses, "fan fold" tape simplified handling as the tape would refold into a "takeup tank" ready to be re-read. The information density of punched tape was low compared with magnetic tape, making large datasets clumsy to handle in punched tape form.