Oil Painting Basics, Mediums Part 2: What are Historical Oil Mediums, How to use Them, and Which are the Safest Mediums to Use?

While trying to figure out what oil mediums you like can be annoying, happily once you know what you do like, it only gets better. Remember, each artist eventually finds their own groove and their own preference as their ability to paint matures and develops, but each artist also needs a starting point. In Mediums Part 1 and 2, I am hoping to provide that starting point.

In Mediums Part 1, I covered the basics of what a medium is. Here I will be covering historical mediums, how to use them, and a few safer medium options.

Historical Mediums

Traditionally mediums are made up of two parts: a solvent (drying agent) like terpenoids or mineral spirits and an oil (retarding agent) like linseed or stand oil.

Artists of the past and now adjust the ratio of terpenoid to oil in order to either slow down or speed up the drying process. More terps means a faster drying time. More oil means a slower drying time.

Fortunately or unfortunately there are a billion DIY medium recipes all over the internet. When I first started oil painting I found the amount of mediums, the information on each medium, and the knowledge needed to understand that information so overwhelming. So here, let's try to keep it simple.

A Basic Recipe

As stated above, traditional recipes are made of a solvent and oil. Let's first pick out a solvent for our mixture. Below are my top two solvent picks, with a little bit of information about solvents in general.

If you would like a long look at different solvents click here. My top two (even though I try to avoid solvents) are Gamsol and Eco-House Orange Terpene. They are both mostly odorless, and to be honest they are the only options if you don't want to make your work space a fumey unbearable place. In my recipe below I will be using gamsol. Note, all solvents are toxic even if you can't smell them and should only be used in a room with proper ventilation. Keep away from children and pets.

Now that we have our solvent, let's pick out an oil for our mixture. Below are my top two oil picks, with a little bit of information about oils in general.

My top two are Refined Linseed Oil or Walnut Oil. In the section below I have more information on some standard oils or you can click here. In my recipe I will be using refined linseed oil.

Note, my recipe follows the fat over lean rule. I will be going over this rule in depth in my next post. However, as a quick overview, the rule is that your first layers should have less fat or oil in them than your last layers. Some artists adjust their mediums as they paint to account for this, which is what you can see down below in my recipe. I, however, do not. I use a 50/50 ratio of walnut alkyd and oil all of the time. Why I do this will be explained in my fat over lean post.

Recipe:

Leanest: 5 drops of gamsol unto your palette. Dip you brush as needed. As you progress with your painting add more fat to your medium.

Leaner: 4 gamsol / 1 drop oil

Lean: 3/2

Fatty: 2/3

Fattiest: 1/5 drops of oil

Some additional Oils and their information:

Safer and almost Toxic Free Mediums

Over the last decade or so, paint brands have started to include non-toxic medium options to their catalog. These options do not have spirits or terpenoids in them, and instead utilize other drying agents. The toxic free options, however, do have a longer drying time than their solvent counterparts.

Some solvent free options are Gamblin Solvent Free Fluid Medium (I find this medium to be a little too runny for my tastes, but it works well), Gamblin Solvent-Free Oil Gel Medium (this is a very thick gel, that I do not love, but it does create strong impasto brush strokes), and M. Graham Walnut Alkyd Medium (which is what I use).

What do I use?

I use 50/50 walnut oil to M. Graham walnut alkyd. I do prefer Gamblin's gaklyd lite to the walnut aklyd, but as I have small children and pets, a solvent free studio space is a must.

Note! All mediums, even if they are solvent free should only be used in a well ventilated room. Do not sleep or eat in the same space that you are painting.

And there we have it, a simple recipe that is a good starting point for any artist wanting more control over their medium than a premade medium affords them. Is there anything that you would add? Let me know in the comments.

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This is a rewrite of two of my original blog posts: Types of Mediums: The Simple Option and Types of Mediums Extended: Oils, Thinners, Mixtures, Questions, etc.