There are many aspects of painting that the artist can make for themselves using the raw ingredients. This not only saves money but gives the artist more control over the product itself. One element that can be made by the artist is the varnish. There are many types of varnish for use with oil paints, but the best one for the artist to make up themselves uses damar resin. It has two main benefits, it’s fairly cheap and it enable the artist to make up different strengths of varnish to suit different purposes.
Damar resin, that is the best type, comes in hard lumps. This will need to be dissolved to be of use. You’ll need a glass jar with a lid (a large jam jar should do), some muslin and artists quality turpentine. Make sure the jar is fully dry, with no trace of dampness, and warm. If required, warm it gently in a microwave.
Crush the resin lumps into smaller bits and using and old cup put 1 measure of the crushed damar into a piece of the muslin and tie it at the top leaving a length of string free. Using the same cup that you used to measure the resin, put 3 measures of turpentine into the jar.
Now, hang the bag of resin in the jar so that the resin is submerged but the top of the bag and string is above the level of turpentine. Close the lid on to the string so it suspends the bag in position. Leave this for a few days, after which the resin should have fully dissolved. The purpose of the bag is to retain the impurities in the resin, so when ready, lift the bag out and discard. The varnish is now ready, but allowing it to stand for longer will make sure any impurities that did manage to escape the bag sink to the bottom of the jar.
Adding a tiny amount of stand oil (no more than 1 part stand oil to 20 parts damar varnish) will help prevent the varnish cracking or blooming over time. Use the varnish as a final coating for any painting in oil including pet portraits or house portraits.