Varnishing Demo

November 23rd: I finally witnessed a demonstration of varnishing, given by Juan Martinez at the school.

The painting had been left to dry for over a year, although only 6 months is needed. Any earlier than that and there's a risk that the varnish will bond with the uppermost paint layers. And the lowest layers may not have settled yet.

Juan washed his painting gently with a damp cloth on a flat surface. Then he opened up a box of Gamblin's Gambar varnish and mixed the 2 components -- resin chemicals dissolved with solvent. GAMBLIN's is the best brand becase it does not yellow over time and remains easy to remove with mild solvents for cleaning in the future (so that the paint layers won't be harmed). Adding it as the top layer of a painting saturates the colors and intensifies the transparency of glazes.

Wearing rubber gloves, Juan mixed only what he needed and poured it into a flat pan. The varnish can't be stored for long once mixed. If it's kept longer than 6 weeks, the varnish loses its UV protection and other qualities.

Re: application.... Instead of a brush, he picked up a sponge edger (for house painting), dipped it in a pan of varnish, wiped off the excess, and then applied a single thin coat to the entire painting.



It looks like a coat of water. But the mineral spirits soon dissolve, leaving a glossy finish. After drying for 24 hours, the painting can be given a second coat to make it glossier. Only 2 layers are necessary.

I found an online demo from Gamblin here.