Conservation is the care and preservation of an important item.
Restoration involves repair and consolidation when damage or distortion occurs.
With time, paintings often become discoloured through the accumulation of surface grime and later applied resin varnishes which become yellow or brown with age.
Cleaning forms part of the Conservation process, freeing the painting of dirt, which can work its way into the fine cracks in the paint surface and induce flaking. A discoloured varnish, when correctly analysed and removed, can allow the original colours of the painting to be appreciated.
Sometimes a canvas might be torn or damaged. It might sag or have dents and bulges. The paint might be cracking and begin to flake. Paintings on panel may become distorted and split or be insect damaged. In such cases the painting may require Restoration through repair, consolidation, or lining with a new canvas, followed by careful filling and considerate minimal retouching to the repaired areas.