You will need:
Portuguese gum turpentine
jar with lid
VCA cleanser and kitchen towels to clean equipment and brushes
Put the dammar resin in the nylon stocking and close with a knot. Hang the stocking in the jar and add Portuguese gum turpentine. Any impurities remain in the stocking. Allow the resin about a week to dissolve, depending on the amount used. Remove the stocking. The varnish is now ready for use.
Proportions are measured in volumes: use a cup or a tumbler, for instance.
You can use dammar varnish: as a medium: one part dammar resin + 2 parts turpentine as a final varnish: 1 part dammar varnish + 5 parts turpentine or 1 part dammar varnish and 20 parts turpentine (retouching varnish) standard medium for oil paint: 3 parts dammar varnish and 1 part linseed oil
If you need a lean varnish use more turpentine. A richer varnish needs more linseed oil. Suspend the stocking in the pot or it will stick to the bottom. Dammar resin comes from Indonesia. Gum turpentine is distilled from pine tree resin.