Reconditioning is the process of putting a piano back in good condition by cleaning, repairing, and adjusting for best performance with parts replacement only where necessary. This is most appropriate for a piano with only moderate wear or those of medium value with average performance requirements. In the short term, leather and felt compact, affecting the adjustment (regulation) of the parts. The action becomes uneven and less responsive, and the piano's tone loses dynamic range. Squeaks and rattles may develop. Routine maintenance such as hammer filing, regulation, voicing, and tuning will correct these problems and maintain the piano in near-new condition. After extended or very heavy use, action parts become severely worn. Leather and felt wear thin. Keys become wobbly, hammer felt gets too thin to produce good tone, and the action becomes noisy. Regulation adjustments reach their limit. In addition, piano strings may begin breaking and the copper windings of bass strings lose resonance. After decades of exposure to seasonal changes, the wood of the soundboard, bridges, and pinblock is weakened. This causes loose tuning pins, poor tuning stability, and further loss of tone. By this time the piano's finish will often be scratched or faded. Reconditioning may include: Thorough cleaning of action and insides, repair or replacement of damaged parts as needed. Also typically including such jobs as felt replacement, hammer filing or replacement, and partial restringing. Adjustment, regulation, tuning, and voicing to return all parts to proper function, reduce mechanical noise, and improve tone may also be needed as well as case finish touch-up or polishing. Reconditioning does not involve replacing major components such as the soundboard, bridges, pinblock, and most action parts. This means the performance and life-span of an older piano will not be restored to new. Instead, reconditioning is designed to improve a piano's performance, keeping in mind both costs and benefits.