Loosen Up! How Oil Painting Mediums Can Transform Your Brushwork

Understanding paint consistency, mediums, and the art of letting your brushstrokes show.

The Beauty of a Visible Brushstroke

Recently, a fellow artist and friend reached out to me with a frustration I think many painters can relate to. He told me how much he loved the loose, expressive quality of my paintings, particularly the way my brushstrokes remain visible. But no matter how hard he tried, he couldn't seem to achieve that same effect in his own work.

We talked about paint, brushes, and technique, and I shared a few things that have made a difference in my painting process.

I use good-quality oil paints, particularly Gamblin and Sennelier, and I use painting mediums to help control how the paint moves across the surface. Three mediums I frequently reach for are Chelsea Classical Studio Fat Medium, Gamblin Refined Linseed Oil, and Gamblin Solvent-Free Gel. I also reach for wide, flat brushes more often than you might expect, even when painting something as delicate as a flower.

But here's what I really want other artists to understand: loose painting doesn't mean giving up control. It means learning where control matters and where to let the paint do its thing.

And sometimes, the secret is in what's mixed into your paint.

 

First, Let's Talk About Paint Quality

Before we get into mediums, let's start with the paint itself.

Not all oil paints behave the same way. Artist-grade oil paints generally offer carefully selected pigments, consistent handling characteristics, and formulations designed for professional use. However, even among excellent brands, some colors are naturally stiffer, softer, more transparent, or more fluid than others.

Two brands I enjoy working with are:

• Gamblin Artist's Oil Colors — Known for their artist-grade oil paints and extensive range of painting mediums.

• Sennelier Artists' Oil Colors — A historic French paint manufacturer whose oil colors include formulations with rich, buttery handling qualities.

When I load my brush, I want enough body in the paint to leave a beautiful mark. I don't want it so stiff that it drags unwillingly across the canvas, but I don't want it so thin that every brushstroke disappears into a smooth film.

Finding that balance is where mediums become particularly useful.

 

What Exactly Is an Oil Painting Medium?

A painting medium is something you add to oil paint to change how it behaves.

Depending on the medium, you can alter the paint's:

• Viscosity: How thick or fluid the paint feels.

• Flow: How easily it moves off your brush.

• Transparency: How much of the underlying painting shows through.

• Drying time: How quickly the paint becomes touch-dry.

• Gloss: Whether the dried surface appears more matte or glossy.

• Texture and body: Whether the paint holds ridges, levels out, or retains visible brushmarks.

The important thing to remember is that mediums are not all interchangeable.

Some make paint more fluid. Others make it thicker. Some accelerate drying, while others slow it down.

And using more medium isn't necessarily better. In fact, adding too much of certain mediums can work against the very brushwork you're trying to create.

 

Understanding the Different Types of Oil Painting Mediums

1. Linseed Oil: The Traditional Favorite

Linseed oil is one of the most familiar mediums in oil painting, and Gamblin Refined Linseed Oil is one I personally use.

Adding a little linseed oil generally makes paint more fluid, improves its flow, increases gloss, and can enhance transparency.

What I like about it: A small amount can help a stiff paint move more easily without completely sacrificing the character of the brushstroke.

What to know: Extra oil can lengthen drying time and increase the risk of yellowing over time, particularly in light colors. Too much can also make your paint slippery and cause your brushmarks to flatten.

Best for: Traditional oil painting, blending, glazing, and improving the flow of stiff paint.

2. Stand Oil: Smooth, Glossy, and Wonderful for Glazing

Stand oil is linseed oil that has been heated under controlled conditions, producing a thicker, more viscous oil.

Despite its thickness, it helps create smooth, enamel-like paint films when properly diluted in a suitable medium mixture.

It tends to level brushmarks rather than preserve sharp ridges.

Best for: Smooth blending, glossy finishes, and transparent glazes.

My advice: If you're trying to create bold, visible brushstrokes, stand oil probably isn't where I'd begin. Its leveling properties can work against that goal.

3. Walnut Oil: A Lovely Alternative

Walnut oil is another traditional drying oil used in painting.

It can improve paint flow and is often chosen for light colors because it generally has less tendency to yellow than linseed oil.

It is also commonly associated with a somewhat slower drying rate.

Best for: Artists who enjoy traditional oils and want a fluid medium for lighter passages or gentle blending.

Keep in mind that the drying behavior of your paint also depends on the pigments and the rest of the formulation.

4. Alkyd Mediums: When You Want Your Paint to Dry Faster

Alkyd mediums are popular because they can speed up drying while modifying how oil paint handles.

Two examples worth exploring are:

Gamblin Galkyd

Galkyd increases flow and gloss, enhances transparency, and speeds drying. It can be useful when you want to work in layers without waiting as long between painting sessions.

Winsor & Newton Liquin

Liquin is a family of alkyd mediums, not just one product. Different versions are formulated for different effects, from smoother flow to thicker texture.

Best for: Painters who work in layers, need faster drying, or want to adjust flow without relying solely on additional drying oil.

One caution: alkyd mediums can vary dramatically in consistency. A fluid alkyd medium may soften your brushmarks, while a gel or impasto formulation can help preserve texture.

5. Gel Mediums: A Great Choice for Expressive Brushwork

Now we're getting into territory that I think will interest painters who love visible brushstrokes!

Gel mediums can change the body and handling of oil paint without making it excessively runny.

Some gels help the paint retain its shape, while others are designed to improve flow or leveling. The specific formulation matters.

One I use is Gamblin Solvent-Free Gel, which is designed to increase flow and transparency while maintaining a more gel-like consistency than a liquid medium.

Best for: Painters who want more control over paint handling without automatically thinning their paint to a watery consistency.

Remember that a gel is not necessarily an impasto medium. If you want dramatic peaks and ridges, choose a product specifically formulated to retain texture.

6. Impasto Mediums: Let Those Brushstrokes Stand Proud!

Impasto is the technique of applying paint thickly enough that the physical texture of the paint becomes part of the artwork.

Impasto mediums are designed to help artists build body and texture. Depending on the product, they may increase the volume of paint, help it retain peaks, or accelerate drying.

Some products are formulated specifically for thick applications, while others are better suited to moderate texture.

Best for: Bold brushmarks, palette-knife painting, textured florals, and paintings where the paint itself becomes part of the visual experience.

If you love seeing individual brushstrokes, this is a category worth exploring.

But here's something important: you don't need thick impasto to paint loosely. A relatively thin, confident brushstroke can be every bit as expressive as a thick one.

7. Solvent-Free Mediums: Another Option Worth Understanding

For artists who want to reduce their exposure to solvents, there are solvent-free oil painting mediums.

These products use oils, alkyds, or other compatible ingredients to change the handling characteristics of paint without adding traditional petroleum-based painting solvents.

They can be especially appealing for artists working in smaller studios.

However, solvent-free doesn't automatically mean hazard-free. Good ventilation, safe handling, and proper disposal of oily materials still matter.

Best for: Artists who prefer to paint without adding mineral spirits or turpentine to their colors.

8. Chelsea Classical Studio Fat Medium: A Personal Favorite

One of my favorite mediums to use is Chelsea Classical Studio Fat Medium. I love working with traditional, plant-derived materials, and I particularly enjoy the wonderful lavender aroma. It certainly makes spending hours at the easel a more pleasant experience!

But the fragrance isn't the only reason I love it. It works beautifully with my oil paints.

Chelsea's Fat Medium is formulated with drying oils and lavender spike oil essence. It helps improve flow, adds gloss and transparency, and allows me to adjust the consistency of my paint.

I particularly enjoy how it helps the paint move across the canvas. When I'm working loosely, I want my brush to glide naturally while still leaving behind those beautiful, individual marks that give a painting character.

Best for: Later layers of oil paintings, glazing, improving paint flow, and artists who enjoy traditional oil-based painting mediums.

What to know: Because this is a fat medium, it's generally better suited to later layers of a painting when working with traditional fat-over-lean techniques. It isn't something I'd recommend adding generously to every layer.

And while its ingredients are plant-derived, lavender spike oil essence is still a solvent. Natural doesn't automatically mean harmless, so good ventilation and safe studio practices remain important.

You can explore their products at Chelsea Classical Studio.

 

A Quick Comparison of Oil Painting Mediums

Medium	Main effect	Brushstroke character
Linseed oil	Improves flow and gloss	May soften ridges
Stand oil	Smooth, glossy leveling	Reduces visible texture
Walnut oil	Fluidity and gentle blending	Can soften marks
Fluid alkyd	Faster drying and improved flow	May level marks
Gel medium	Adjusts body and flow	Depends on formulation
Impasto medium	Builds texture and volume	Helps preserve raised marks
Solvent-free medium	Modifies handling without added solvent	Depends on formulation
Chelsea Fat Medium	Improves flow, gloss, and transparency	Can soften marks depending on amount used

The Brush Matters Just as Much as the Medium

One of the things I mentioned to my friend was my preference for wide, flat brushes.

I love painting flowers, trees, feathers, and landscapes, all subjects that might make you think I'd be reaching for tiny round brushes all day long.

But I don't.

A wide, flat brush allows me to lay down a beautiful block of color in a single movement. I can use the broad face of the brush for a generous stroke, turn it sideways for a narrower mark, or use the corner for a small detail.

The shape of the brush helps create variety without constantly changing tools.

And there's another advantage: a larger brush discourages unnecessary fiddling.

When you're holding a tiny brush, it's tempting to keep adding little corrections. A larger brush encourages you to think about shapes, color relationships, and the overall impression.

For me, that's where painting becomes exciting.

Why Your Brushstrokes Keep Disappearing

If you're struggling to achieve a loose painting style, consider whether any of these habits sound familiar.

You're blending too much. Every time you go back over a brushstroke, you risk disturbing the beautiful mark you just made. Sometimes the first stroke really is the best one.

You're using too much medium. A generous amount of fluid medium may make the paint glide beautifully, but it can also cause the marks to level out.

Your brush is too small. Tiny brushes encourage tiny decisions. Try a brush that feels almost ridiculously large for the subject.

You're not loading enough paint. A nearly dry brush behaves very differently from one loaded with rich, buttery color. Experiment with how much paint you pick up.

You're correcting every little thing. This is probably the hardest habit to break. Not every petal needs a perfect edge. Not every leaf needs a vein. Sometimes a single stroke of color tells the whole story.

My Favorite Exercise for Loosening Up

Here's something I'd encourage any painter to try.

Choose a simple subject, perhaps a flower, a piece of fruit, or a small landscape.

Use a wide, flat brush and a limited palette of colors.

Paint the subject three times:

Painting One: Straight From the Tube

Use your oil paint without added medium. Pay attention to how the paint holds its shape and how the brush drags across the surface.

Painting Two: With a Small Amount of Fluid Medium

Add a little linseed oil or another appropriate fluid medium. Notice how the paint moves, how the edges change, and whether your brushmarks remain visible.

Painting Three: With a Gel or Impasto Medium

Choose a product designed to retain some body or texture. Experiment with leaving the brushstrokes exactly as they land.

Now compare the three.

Which painting has the most interesting marks? Which one feels the most spontaneous? Which paint consistency gives you the most control?

You may discover that your favorite is the one with no medium at all!

That's the point of the exercise. It's not about finding a magical product. It's about learning how the materials respond to your hand.

A Few Important Rules Before You Start Mixing

Oil painting mediums are wonderful tools, but they need to be used thoughtfully.

• Start small. Follow the manufacturer's recommended proportions rather than adding generous amounts of medium.

• Respect fat-over-lean principles. When working in layers, consider the flexibility and composition of the paint films, not just how oily or thin they look.

• Avoid excessive solvent. Solvent can reduce viscosity, but it isn't a substitute for a properly formulated painting medium.

• Consider drying times. Thick paint and slow-drying colors may remain soft beneath a dry-looking surface.

• Use good studio safety practices. Keep your workspace ventilated, read product safety information, and store or dispose of oily rags safely because they can pose a spontaneous-combustion hazard.

When trying a new medium, I recommend reading the manufacturer's instructions and experimenting on a small practice panel before using it in an important painting.

Learning to Leave the Paint Alone

When my friend asked how I get my brushstrokes to show, I could tell him about my Gamblin and Sennelier paints, the mediums I use, and my beloved wide, flat brushes.

All of those things matter.

But I think the biggest lesson in loose painting is learning when to stop.

A brushstroke has its own personality. It has a beginning, a direction, a little variation in color, and sometimes a wonderfully unexpected edge.

When we keep fussing with it, we can erase all that character.

I love seeing the individual strokes in a painting. They remind me that a real person stood in front of that canvas, made decisions, changed direction, and left behind a little evidence of the process.

My advice to anyone trying to loosen up is simple: experiment with your materials, use a bigger brush, give yourself permission to make imperfect marks, and resist the urge to blend everything into submission.

Sometimes the most beautiful brushstroke is the one you were brave enough to leave alone.

Happy painting!

Sheila Huyett

Sheila Huyett Fine Art

Explore My Paintings

Additional Resources for Oil Painters

If you'd like to learn more about the different mediums available and how to use them, these manufacturers are excellent places to begin:

• Gamblin Artist Colors — Oil painting mediums, artist colors, and educational resources.

• Chelsea Classical Studio — Traditional oil painting mediums and lavender-based products.

• Sennelier — Professional oil paints and traditional painting materials.

• Winsor & Newton — Information about Liquin mediums and traditional oil painting techniques.

• Royal Talens — Painting mediums, oils, and educational resources.