Magnetic tape or timecode-marked digital track at reel start — syncs material and threads editing machines. Obsolete in digital, still used in analog workflows.
Leader
For a long time, the leader was the indispensable opening of every magnetic tape reel in the editing suite. Before picture editing begins, several meters of unrecorded or timecode-marked tape are wound on — this piece allows the editing machine operator to thread the reel without immediately running into critical material. The leader creates a safety buffer and gives the technical staff time to stabilize and correctly synchronize the machine.
In practice, it works like this: The leader tape is marked with clear timecode numbers — usually a countdown from 00:10:00 to 00:00:00 or second markers every five seconds. These markings allow multiple reels to be precisely matched and guarantee flawless synchronization. The editor uses these numbers to check if the editing machine is running correctly and if all source tapes are running at the same speed — crucial when working with multiple synchronized audio tracks.
In the digital workflow, the physical leader has long been obsolete. Modern NLEs (Non-Linear Editors) generate sync codes automatically; the editing computer no longer needs a mechanical threading buffer. Nevertheless, tapes with classic leaders can still be found in professional broadcast and film archives — a consideration for compatibility and for cases where older material needs to be transferred back to linear editing machines. Anyone working with analog magnetic tapes or U-matic cassettes will have to understand the leader.
A practical tip: Good leader tape is always unrecorded and magnetically neutral — never use cut-offs or degraded material. Damaged leaders lead to synchronization errors and unnecessary false starts. In professional archives, the leader is therefore treated like the material itself: carefully labeled, protected from heat and magnetic fields, and regularly checked.