Wick trimmers are essential for maintaining your candle's wick properly. Keeping your wick nice and trim will ensure a clean, even flame for a longer-lasting candle and maximum fragrance. These wick trimmers are long enough to reach into deep candle vessels when they have burned low. Your wick should be trimmed after every 4 hours of burn time. Let the candle come to room temperature, then trim the wick to 1/8-inch before relighting. This will prevent an overly large flame, which will burn too hot and fast- which can cause black smoke and effect the efficiency (and safety!) of your candle.