Incorrect conservation treatments can arise from the assumption that problems of damage to the support should be resolved by prioritizing the painted image, and by working to arrive at a utopian recovery of the original condition. Such actions have nothing to do with the current practice of restoration. Although a direct inheritor of artisan traditions, current restoration is based on minimal intervention, which features respect and reversibility as its primary pillars. The article discusses the widespread deterioration due to inadequate restoration of paintings from private collections. Numerous examples illustrate damage caused by wrong choice of materials or insufficient technical skill. The techniques of marouflage and dimensional changes are presented, together with their often negative consequences.