Many players are careless about how they store chalk. During the rainy season or in a humid pool hall, chalk can soften, clump and turn sticky on the surface. Plenty of people hate to throw it away and wonder whether damp, clumped chalk can still be used. The short answer: mildly damp chalk can be dried and used for a while; once it is badly clumped, sticky or discoloured, do not keep using it — it will hurt your feel and may damage the table and tip.

Mildly damp chalk is only slightly soft on the outside, with no muddy clumps or odour. This is simply chalk absorbing moisture from the air. The fix is easy: place it somewhere cool and well ventilated to air-dry naturally. Never dry it in direct sunlight or in an oven — high temperatures change the chemical composition inside, hardening and cracking the powder and permanently reducing friction. Once dry, lightly sand the surface with the sandpaper on the chalk holder to remove the deteriorated outer layer. Try applying it: if it goes on smoothly and does not stick to the tip, it can still be used. Performance will be below that of a fresh cube though, with less consistent friction and a higher chance of miscue on heavy english.

If the chalk has clearly clumped, turns muddy when rubbed, feels sticky when pressed, or shows mould spots and an odour, it must be discarded. Once damp and clumped, the fine granular structure of the powder is destroyed by moisture and the particles stick together in lumps. When applied, instead of a thin film on the tip surface the paste fills the pores of the tip and blocks them. The tip loses elasticity, its grip on the ball drops sharply, and slipping and miscues become frequent.

Second, muddy damp chalk sticks to the cue ball in quantity during play and is carried onto the cloth. Once dry, the clumped powder lodges in the cloth fibres and is very hard to remove, accelerating cloth wear and leaving stubborn stains. Mouldy chalk also breeds fungus; inhaling the dust released when applying it can irritate the respiratory tract and affect your health.

One more misconception to clear up: a slightly damp surface does not mean the chalk has gone bad. Sweat from your hands during a session only moistens the surface briefly — just wipe it dry and leave it somewhere ventilated. But storing it long term in a damp cue case or next to a drink cup lets moisture penetrate inside, softening and clumping the whole cube — that is deep moisture damage, and recovery will be poor.

For everyday storage, keep chalk in a sealed chalk box away from drinks and damp floors. In the rainy season put a small packet of desiccant in your cue case to reduce humidity. Do not stockpile large quantities for long-term storage, or you risk losing a whole batch to damp.

In short, do not blindly keep using damp, clumped chalk. Mildly damp chalk can be used temporarily after air-drying, but not in important matches. Discard chalk that has clumped, turned sticky or grown mould, to avoid damaging tip and cloth while also preventing missed shots and health risks.