Black and white smoke is used to represent the cardinals' decisions each day, as they are sequestered and cannot share this news directly. If one candidate doesn't receive the necessary two-thirds ...

At the end of each voting round, black smoke means a new pope has not yet to be selected, while white smoke indicates a new pope has been chosen.

Meanwhile, white smoke is produced using a much cleaner fuel mix and a more powerful oxidiser. Potassium chlorate (KClO₃) – even more reactive than perchlorate – ensures a hot, vigorous burn.

Black smoke indicates a non-conclusive answer, and white smoke indicates that a new pope has been selected. Here's what to know about the black and white smoke used during a papal conclave.