Cotton is used too for many miscellaneous purposes, including the manufacture of lamp wicks and even of billiard balls.
Let candles cool completely before trimming the wicks.
Jar candles often use core wicks, as do votive candles.
You can use the same wicks that are used for paraffin wax candles.
In fact, the role of Martin Wicks, the new Energy Minister, has been absolutely atrocious.