Winsor & Newton
Winsor & Newton Artists' Picture Cleaner
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.
Please note, however, 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 colour appears to be coming off the painting.