How to make scented candles last longer？

People all enjoy the relaxing fragrance of candles, but sometimes the smell don’t last as long as expected. Usually, candles’ lifespan depends on the material used, but there are some methods that can make the scented smell last longer.
Firstly, the quality and thickness of the wick are vital because a flame’s size all depends on the wick. Once lit, a wick draws up the wax through its centre to fuel the flame at the top. The wax will be burned and vaporized until it eventually diminish without anything left. The larger the flame, the more wax that gets burned. Thus, it’s necessary to choose a candle with a proper wick so that the flame can burn through the wax at a steady rate.
In addition, the type of wax is of importance to make scented candles last longer. Some kind of waxes melt at a low temperature, which means they can burn at a faster rate. As we all know, natural waxes take longer to burn than paraffin waxes, but natural waxes also can’t hold too much fragrance, so the resulting scent will be less intense. 
Finally, it’s a good way for making scented candles last longer to melt any leftover wax in an oil burner. You can gently scrape out the loose pieces of wax and place them in the top of the burner with a lit light underneath. The heat from the light will melt the scented wax so you can keep on enjoying the original candle’s scent a little longer.