Too little MEKO: skin forms on the paint surface in the can within weeks of production — visible as a rubbery layer on the paint surface when the can is opened. The skin must be removed before use. Too much MEKO: the paint takes significantly longer to dry after application — the excess MEKO volatilising during drying continues to temporarily deactivate driers. In normal practice at 0.15–0.25%, the balance is well-maintained. If you experience skinning issues despite correct MEKO addition, check that the cobalt drier level is not too high, that cans are fully sealed, and that storage temperatures are not excessive (> 45°C accelerates drier activity even in sealed cans).