It is somewhat necessary to learn of the oils mediums and solvents that are used in the creation of an oil painting. Linseed oil has been the standard for many years. Linseed oil coupled with a solvent will dry quite readily. The main drawback is that it has a tendency to yellow with age. Stand oil is a form of polymerized linseed oil. It dries a bit slower because of it’s thickness, somewhat like honey. It will not yellow as much as linseed oil, and it is also crack resistant.
Some other oils are, safflower oil, walnut oil, and poppy seed oil. These also, do not yellow as much as linseed oil.
The traditional resins used by artists are damar and copal. I personally prefer to use copal resin in my painting. Copal seems to dry with a tougher finish than damar so, it should stand up better against most cleaning solvents.
Turpentine is of course the first one that we think of however, there are others to consider. Turpenoid is a turpentine substitute that does not emit the strong vapors as turpentine. It also, washes out well. The one disadvantage is that it does not mix well with damar. I prefer to use odorless mineral spirits.
If you find that you are allergic to solvents, then you might try using water miscible oils. You can check with the various art suppliers for mediums to use in this system.
Mediums are used for thinning your oil paint. You may find that the paint as it comes from the tube, is a bit heavy, so you may want to thin it some to make for easy application. Also, for painting wet on to wet, you will find it easier to apply the thinner paint over the lower layer without it mixing in or blending in to the lower layer of paint. To thin your paint, it is best to use a combination of oil and solvent, as too much solvent can break down the binders in the paint. I have suggested some recipes of oils mediums and solvents below.
- one part linseed oil to five parts solvent – This would be the leanest.
- one part linseed oil to one part solvent. Please note: You can always substitute stand oil for linseed.
- one part stand oil – one part copal resin or medium – five parts solvent. I use this most as my all purpose medium.
- one part stand oil – one part copal – three parts solvent. A very fat medium
One exception to the rule: Solvent only can be used to thin the paint in the under painting since it will dry faster. As for breaking down the binder, that should not be an issue since the oil in the subsequent layers will be absorbed by that first layer.