Finish is the term used to describe the final layer on a painting or object. This can relate to the surface sheen, texture or condition examples of which could be Gloss finish, Stucco finish and Antiqued finish. Finishes can be achieved by using various treatments or coatings such as liquid varnishes, paint mediums or Craquelure glazes depending on the kind of materials that are being used. An untreated finish is usually described as natural.
Varnish is used to alter the surface sheen on a painting with the three most commonly recognised finishes being Matte which gives a flat, dull finish, Gloss which gives a high shine and Satin which gives a smooth, slightly shiney finish somewhere between matte and gloss.