Artists' Picture Cleaner is a liquid which is designed for the cleaning of varnished paintings and is an excellent product for this purpose. It works by dissolving linseed oil oxidation and will remove surface dirt and the products of oxidation in the old varnish. It contains an emulsified mixture of Copaiba balsam, dipentene and pine oil with ammonia.
You will find that the liquid settles out in two layers so you will need to shake well before use and thinning is not recommended. 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 seems to be coming off the painting. Artists' Picture Cleaner can effect an unbelievable improvement on paintings both simply and inexpensively but if you are in any doubt about the condition of the original painting or if the varnish is cracked, let the necessary work be done by an expert.
Winsor & Newton Artists' Picture Cleaner is available here in 75ml, 250ml and 500ml bottles.