The final coatings for finished pictures, varnishes protect from the build-up of dirt and grease. Fine Art varnishes should be removable so that paintings can be cleaned. Over time, dirt and dust can get trapped in the varnish and removing and reapplying this will make it as good as new. Available in different finishes, Matt, Satin & Gloss, it is important to wait until oil paintings are thoroughly dry before varnishing (drying time should be at least 6-12 months for conventional oils and 3 months for Griffin Alkyd Fast Drying Oil Colour).
A quality UV resistant artists' gloss varnish that maintains painting for longer. Sealing the microscopic pores on the oil paint film provides resistance to dirt and grease as well as balances out the surface sheen.
Removable, for the purpose of re-varnishing, use a solvent such as Artists' White Spirit or Distilled Turpentine.