Oil Mediums: A Simple Guide
Oil paints are, at root, an uncomplicated material — just pigment suspended in an oil. Like most things, however, there’s more to the story. A quick trip through your favorite art supply store reveals that there is more than one type of oil medium, and figuring out which to use for what circumstances can be a challenge. Among the most commonly used oil mediums are linseed oil, walnut oil, stand oil, and safflower oil. Each oil is unique in its viscosity, texture, and drying time. Let’s dig into these properties to help you make the right choice for your work.
To know which oil to use, it’s important to know where each fits into the painting process. Oil paints consist of pigments in an oil medium, usually linseed oil. Over time, that oil hardens, keeping pigment particles suspended in a beautiful translucent oil film. The thick, buttery paint can be used straight from the tube in some circumstances. At other times, you’ll want to thin the paint or extend it to create glazes or to improve the paint’s flow, or affect the drying time. That’s when additions of small amounts of oil medium comes into play.
As you dial in your brush techniques and color choices, it becomes increasingly important to understand the nuanced differences between various oil mediums to better control your color and the longevity of your work.
Here’s what to know about each oil.
Linseed Oil
Linseed oil is derived from flax seed and is perhaps the most widely used oil medium in oil painting. Linseed oil has been used for centuries, and when used effectively has proven to hold up well over time. While a distinct advantage of oil paints is its slow curing time, when compared to other oils, linseed oil has a relatively fast drying time of three to four days, depending on the amount used. Cold-pressed linseed oil may take longer to dry.
Stand Oil
Stand oil is a thicker form of linseed oil. It has a syrup-like consistency and can be ideal for luminous effects, glazes, and achieving a glossy finish. Its extended drying time can be a drawback if you prefer to work quickly. You might also find that it needs to be thinned with solvent to make it more workable.
Walnut Oil
Walnut oil, extracted from walnut kernels, has a lighter color compared to linseed oil and dries slightly slower, making it a good choice if you prefer your paintings to remain wet and workable for longer periods of time. It’s a great medium for blending, softening edges and refining details over an extended period without the paint becoming tacky or stiff.
Safflower Oil
Safflower oil is more pale and has a lighter consistency than linseed and walnut oils. It has a slower drying time compared to linseed oil, making it effective for blending layers over time or wet-on-wet painting techniques.
Poppy Oil
Poppy oil is a vegetable oil extracted from the seeds of the poppy flower. It has a thinner, lighter consistency than linseed oil and stand oils, making it effective for thin layers of paint. Poppy oil, like walnut and safflower oil, dries more slowly than linseed oil. The unique, transparent properties of poppy oil are often described as being well suited for whites and colors lighter in value.
How do they hold up over time?
When considering the archival qualities of these oil mediums, linseed oil and walnut oil are generally considered to be more archival than stand oil and safflower oil. With each of these oil mediums, however, it’s important to use them in the right amounts. Linseed oil, when used in small quantities, has proven to be effective, but with excessive use can lead to yellowing and cracking. Poppy and safflower oils are considered to be the least yellowing of these oil mediums, but there is some concern about cracking and the durability of the paint film over time.
Final Thoughts
Which medium to use when basically boils down to need and technique. Linseed oil is a tried-and-true medium. Use it sparingly and follow the “fat over lean” rule to minimize yellowing and cracking. Consider using it for both alla prima and glazing techniques. Use walnut oil if you prefer to work wet-in-wet over extended periods of time. When looking for thin, luminous layers of light color, consider poppy and safflower oil, but know that those layers could require longer drying time.
Meet the Artist
Scott Maier is an artist and a content contributor to artistsnetwork.com. He’s also the author of the instructional art book See, Think, Draw: An Easy Guide for Realistic Drawing and Beyond.
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