Carrom powder is sprinkled on the board's surface to reduce friction, thereby enabling smoother and faster play.
Broadly speaking, there are two basic types of carrom powder. The traditional commonly available powder is boric acid based, and works quite well. However, some stores now offer a new type of super fine powder (usually available in small plastic bottles), which is non-toxic and performs brilliantly. Since a very small quantity of the latter needs to be applied each time, it is actually cost effective and less messy!
For optimum performance and longer life of your board, spray a VERY small quantity of super fine powder before each game, and never use two different types of powders simultaneously. If you wish to switch from one kind of powder to another, lightly wipe off the old powder with a soft cloth completely before using the new powder.