Are you looking for Billiard Chalk?
Do you have a particular brand in mind?
Playing consistent pool can be next to impossible without using quality chalk.
Have you ever been shooting pool where you make several shots in a row? You are on a roll and then all of a sudden on a simple shot, your cue tip slides right off of the cue ball and you miss the shot or don't even make contact with your object ball.
This is known as the dreaded miss cue.
My personal preference when deciding on which chalk to use is almost always Masters Chalk. I have played with National Tournament chalk and many other off brands and the others just do not seem to cling to the tip and prevent the miscue the way Masters Billiards Chalk does.
Masters chalk is not hard to find. Pretty much any Billiards supply store will have it in stock. You will probably even find it easy enough online looking on eBay or Amazon.
I hope the information here helps you out when deciding which chalk to use and help you to remember to keep you tip conditioned to hold the chalk and give you a smooth hit on the cue ball.
If the tip on your cue is hard and or mushroomed, you will have a much tough time getting the chalk to stick to your cue. You should use a tip tapper or shaping tool or even some fine sand paper to rough up your tip and allow the chalk to take hold.
You can find the tip maintenance equipment along with chalk at your local billiard supply store or inline with a simple google search.
The link above will give you a good over view on our free billiards fundamentals course. You would be surprised how many letters I get from good players saying the course really helped them move their game up a level or 2. Sometimes going back to the basics can do amazing things for your pool game.