Mastic Varnish
The Varnish of the Old Masters
The addition of natural Mastic Resin to Turpentine as a varnish dates back to at least 700 B.C. At the time of the Old Masters, it became common as a finishing varnish, as well as a major ingredient in oil painting mediums. Mastic, being one of the strongest binding resins, is quite permanent. Its varnish has been protecting Old Masters works for centuries.
Mastic Resin
This natural resin is a chewy, light-colored, sap-like substance which grows on the Pistacia Lentiscus tree (an evergreen related to the pistachio tree). It can be found growing almost exclusively on the island of Chios, off the coast of Greece. The word "masticate" (to chew) comes directly from the Greek word for this resin (masticha), as it was first used in chewing gum and other Greek candies.
Instructions for Varnishing with Mastic Varnish
Preparation:
Make sure your painting is dry to the touch, and no areas are still wet
as the paint might run. Paintings can be varnished within 2-3 weeks after
completing the painting, but if you wait longer it is recommended you wait
6 months.
Application:
Use a soft, natural bristle brush (Flat, preferably 1.5 or 2 inches).
Dip the brush into the jar of varnish, and press against the rim to remove
excess varnish. Brush the varnish onto the painting, spreading the varnish
as you go to create a thin layer. Do not scrub very hard, just enough to
spread the varnish around. The varnish will start to set up and get tacky
quickly, so don't go over areas many times. When necessary, dip brush into
jar again and continue brushing onto painting until fully covered with an
even thin layer.
Paintings usually require anywhere between 1-3 coats. Make sure varnish is again dry to the touch and not tacky before applying another coat. Leaving a painting in the sun will usually dry the varnish in 1 day. Depending on climate, you may have to wait a few days to apply another coat.

"Peaches and Yellow Finches" by
David A Leffel
Old Masters Customer
"Santo with Copper and Onions" by
Sherrie McGraw
Old Masters Customer