French polishes are made up from flaked shellac dissolved in methylated spirit, designed to give a good finish on furniture. The types of shellac used can vary in colour from light clear colour to a dark brown colour. The type of colour to use will mainly depend on the type of timber and furniture.
Said to originate from France in the 15/16 hundreds, french polishing is not something that can be achieved by anybody. To french polish the correct way requires practice and lots of patience.