Wick trimmers are used to proper maintain the lamp’s wick. When lamps are burned, their wicks burn uneven and these devices simply cut a straight line across the wick so the lamp can burn more efficiently. Also, by trimming the wick, carbon build-up and left over oil residue are removed.
Wick trimmers can be found in a variety of shapes as many different patents were applied for to construct a better trimmer. Some were complex but most of them found are simple in shape and function resembling scissors.