Editing Reel (section)

==Construction==
{{Unreferenced section|date=January 2012}}

The size of the core is dependent on several factors. A smaller core will obviously allow more material to be stored in a given space. However, there is a limit to how tightly the stored material can be wound without damaging it and this limits how small the core can be.

Other issues affecting the core size include:

* Mechanical strength of the core (especially with big reels)
* Acceptable turning speed (for a given rate of material moving on or off the reel a smaller core will mean that an almost empty reel has to turn faster)
* any functional requirements of the core e.g.
** For a reel that must be mechanically turned the size of the grips that mount it on the mechanical turning device.
** The size of the mountings needed to support the core during unwinding.
** Anything mounted on the cores (e.g. the sockets on an [[extension reel]])

With material such as [[photographic film]] that is flat and long but is relatively wide, the material generally is stored in successive single layers. In cases where the material is more uniform in cross-section (for example, a cable), the material may be safely wound around a reel that is wider than its width. In this case, several windings are needed to create a layer on the reel.