Question: how long do you have to wait before varnishing an oil painting?
Answer: When to varnish For most paintings, there is no need to wait for 6 to 12 months before varnishing with Gamvar. Gamvar can be applied when the thickest areas of your painting are firm. Gently press your fingernail into the thickest area of paint. If it is firm underneath the surface, then it is ready for varnishing.