A candle's wick should be trimmed prior to first use and after each burn time. To trim, let the candle come to room temperature, clear any debris, then trim the wick to 1/8-inch before relighting. The shorter wick length helps create complete combustion, which means less soot is formed while the candle is burning, providing a cleaner burn. It also ensures that candle does not burn too fast or get too hot.