Q: I recently varnished an oil painting with matte varnish,
but I am unhappy with the finish (Grumbacher). Can I varnish the
painting again with a glossy varnish?
A: You can revarnish the painting, but to be safe you
should use the same brand of varnish because changing brands may cause
problems such as blooming, cracking, or yellowing.
--by Camille LaPointe-Lyons