From the manufacturer:
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. Quick drying. Non-yellowing, it does not bloom or crack. Do not use until painting is completely dry (6-12 months). Do not use as a medium.