How does a candle burn?
A candle needs oxygen, fuel (wax) and a wick. All three components have to be in perfect harmony to produce a well burning flame. If there is too much oxygen, the candle will smoke and drip. If there is too little oxygen, the flame will flicker and smoke. If the melting point of the wax is too high or too low and an inappropriately sized wick with poor absorbency is being used, the candle will either burn with a very small flame, with a very large flame, or in the worst scenario, the wick will burn up and the flame will estinguish or the wick will drown in a puddle of wax.