Winsor & Newton Artists' Picture Cleaner is a natural resin/oil emulsion containing ammonia designed for cleaning varnished paintings. It works by dissolving linseed oil oxidation and will remove surface dirt and the products of oxidation in the old varnish. Note that a picture that needs to have old varnish removed should be entrusted to a competent picture restorer. Unvarnished paintings may also be treated with Artists' Picture Cleaner but great care is necessary and the process should be stopped immediately if any color appears to be coming off the painting. Shake before and during use. Clean small areas with cotton wool pads. When cleaning is complete remove any remaining cleaner with distilled turpentine. Batch colour and settlement may vary.