1.	Conductor Stranding: #36 AWG is the recommended stranding for most cords. Although #38, #40, #42, and #44 AWG will yield improved flexibility and cord memory, these strandings are expensive. In some cases the #32 and #34 AWG can be used, but at the expense of cord flexibility. (Please note: stranding refers to the individual strands that compose a multi-strand conductor).
2.	Lay Direction: The C&M standard cable lay is left-hand which yields a right-hand retractile cord.
3.	Tapes and Binders: Decrease retractability of coil cords.
4.	Shield: In cases where shielding is necessary, aluminum polyester or aluminum polyester aluminum tapes are recommended in lieu of stranded metal shields. If a stranded metal shield must be used, spirally applied #36, #38 or #40 AWG strands are recommended.
5.	Snappiness: Insulation materials, primary and jacket, greatly effect the "snappiness" of a cord. Although the following list is very general, it is sufficient for design estimation: a. Very snappy materials: Hytrel, Polyurethane b. Snappy materials: Polypropylene, TPR, Neoprene c. Neutral materials: Polyethylene, Nylon, Surlyn, Some TPRs d. Slow to retract materials: PVC, Some TPRs, Teflons
6.	Thermoplastic vs. Thermoset: Thermoplastic retractile cords are very susceptible to temperature. If a thermoplastic cord is exposed to temperatures in excess of 120°F, it will lose its retractile form. If the application requires a cord to be used in temperatures exceeding 120°F, it is recommended that a thermoset jacketing material be used.
7.	Usable Extension Range: The maximum extension ratio for this definition is 100 percent. For example, a retractile cord containing ten feet of cable in the coil body (excluding tangents) will have achieved a 100 percent extension ratio when that cable has been stretched to its maximum ten feet. Depending on conductor AWG and standing, shielding, and insulation material, some retractile cords can be safely stretched and still retain its retracted form upon return.