Why You Should Use Mediums in Oil Painting
Painting with oils doesn’t have to be confusing or overly technical. But if you’ve ever struggled with long drying times or stiff paint, mediums can make a big difference.
Many painters start out thinning their paint with solvent alone. That’s common—and understandable. But over time, that approach often creates more problems than it solves. Mediums exist to improve how your paint handles, dries, and holds together over time.
In this video, I take the mystery out of oil painting mediums and show you how to use them in a simple, practical way—without overcomplicating things. Be sure to also grab a copy of the Mediums Cheat Sheet below.
What Is a Medium (Really)?
A medium is simply an additive that changes how oil paint behaves.
That’s it.
Mediums can help paint:
Flow more easily
Dry faster or slower
Become more transparent
Create a stronger, more flexible paint layer
The goal isn’t just to make painting easier, it’s also to create a painting that will hold up over time.
Mediums Help Paint Flow (Without Weakening It)
Oil paint contains plant-based oil binders, like linseed, poppy, safflower or walnut oil. But straight out of the tube it can sometimes feel stiff or draggy. A medium can loosen the paint and make it feel more buttery and responsive.
Why not just use solvent?
Early in a painting—like during an imprimatura—solvent is fine. But solvent breaks down the paint binder. Too much of it creates weak, brittle layers.
Mediums, on the other hand, maintain flexibility, which is exactly what you want as you build layers.
Common beginner mistake:
Using solvent throughout the entire painting instead of switching to a medium after the early stages.
Mediums Control Drying Time
If you’ve ever painted thickly and had to wait days (or weeks) for the surface to dry, you already know why this matters.
Some mediums extend drying time, while others, such as Alkyd-based mediums, speed drying time.
And some mediums do more than one thing. Liquin, for example, improves flow and usually allows the paint to dry by the next day, which makes daily painting much easier.
Mediums Increase Transparency (For Glazing)
Some oil colors are naturally transparent, while others are opaque. A medium can increase transparency when you want to glaze.
Glazing should always be done with a medium—not solvent. You want a flexible, oil-rich layer—not a weakened one.
Mediums Change Surface Quality
Mediums also affect how the surface of the paint looks and feels.
For example:
Linseed or stand oil increases gloss
Impasto mediums add thickness and visible brushwork
Choose a Medium Based on What You Want to Achieve
Instead of asking, “Which medium is best?”
Ask, “What do I want the paint to do?”
Things to consider:
Do you prefer thick, textured paint—or smooth, thin layers?
Do you want fast or slow drying?
Do you like a glossy or more satin finish?
Once you know that, you'll be in a better position to choose a medium that supports how you like to paint.
Keep It Simple (Especially at First)
If you want an easy starting point, a good all-around medium like Liquin works well for most situations. You don’t need much—and I demonstrate how little is required in the video above.
As you gain experience, experiment with other mediums and notice how they feel under the brush. Even the same type of medium from different brands may behave a little differently.
This is about building confidence and finding what you like, not collecting supplies.
A Helpful Next Step
To make this even easier, I’ve created an Oil Painting Mediums Cheat Sheet that breaks down common options and what they’re best used for.
👉 Download the Mediums Cheat Sheet
Remember, use mediums to enhance your paint—not replace good fundamentals.
And save your solvent for cleaning brushes. 👍
