Quick answer: Oil became the dominant medium in easel painting because it solved the problems of earlier methods. It dries slowly, so painters can blend and revise; it can be applied as thin, luminous glazes or thick impasto; it stays flexible enough to work on lightweight, portable canvas; and it produces deep, saturated color that lasts for centuries. Once oils were refined in 15th-century Northern Europe and paired with stretched canvas, they suited the portable, framed paintings that defined Western art for over 500 years.
Walk through almost any major museum of Western art and most of the framed paintings on the walls are oils. That is not an accident. Asking why oil is a dominant medium in easel painting means looking at history, chemistry and practical studio needs together. Each part explains a piece of the story.
This guide explains what easel painting is, what came before oil, the specific properties that gave oil its advantage, the role of canvas and paint tubes, and how oil painting mediums extend those properties today.
What Is Easel Painting?
Easel painting refers to paintings made on a portable support (a panel or canvas) placed on an easel, as opposed to murals painted directly on walls or ceilings. The finished work can be framed, moved, sold and hung anywhere.
This portability changed the art world. Paintings became objects that could be commissioned by private patrons, collected, traded and exhibited. The medium best suited to portable, durable, highly finished paintings would naturally dominate, and that medium turned out to be oil.
The easel is more than a stand in this story. Oil paint is usually worked upright so the artist sees the painting as it will hang, and slow drying means a canvas may stay on the easel for weeks while layers build up. A steady, adjustable support is part of the oil painter’s toolkit, which is why studio painters tend to choose their easel as carefully as their paints. Our guide to easels suited to oil painting explains what features matter for that kind of long, layered work.
A Quick Look at How Oil Paint Dries
Oil paint does not dry by evaporation the way watercolor and acrylic do. Drying oils such as linseed contain unsaturated fatty acids that react with oxygen in the air and gradually link together into a solid, flexible film. Surface drying can take a day or more for thin layers, while thick passages may stay soft underneath for much longer, and full curing continues for months.
Pigments affect this process. Some, such as earth colors containing iron or manganese, tend to speed drying, while others dry more slowly. Painters learned to use these differences, placing faster-drying colors in underlayers and slower ones on top.
What Came Before Oil
Fresco
Fresco involves painting pigments into wet lime plaster. It is durable and luminous but must be completed quickly before the plaster sets, and it is permanently attached to a wall. It cannot be an easel painting.
Egg tempera
Tempera, made by binding pigment with egg yolk, was the main medium for panel painting in medieval and early Renaissance Europe. It dries very fast, which means blending is difficult; artists built up tone with fine hatching strokes. Tempera is also fairly brittle and suits rigid wooden panels rather than flexible canvas.
Other methods
Encaustic (pigment in hot wax) was used in antiquity but is demanding to work with. Distemper (pigment in glue) was used on cloth but is less durable and sensitive to moisture.
| Medium | Drying speed | Blending | Flexibility | Portability |
|---|---|---|---|---|
| Fresco | Must finish while plaster is wet | Limited | Rigid (wall) | None |
| Egg tempera | Very fast | Difficult; built by hatching | Brittle; needs rigid panel | Good on panel |
| Encaustic | Sets as wax cools | Requires heat | Moderate | Moderate |
| Oil | Slow (days to weeks) | Excellent | Flexible on canvas | Excellent |
Why Oil Is a Dominant Medium in Easel Painting: 7 Key Reasons
1. Slow drying allows blending and revision
Drying oils such as linseed oil cure by reacting with oxygen, a process that takes days or longer for a paint film to become dry to the touch. That long working time lets painters blend colors directly on the canvas, create soft transitions in skin and sky, and rework passages. Tempera painters had to commit almost instantly; oil painters could take their time.
2. Glazing creates luminous depth
Oil paint can be thinned into transparent layers called glazes. Light passes through each glaze, reflects off lighter layers beneath and returns through the color, which creates a deep, glowing effect. Early Netherlandish painters became famous for this jewel-like richness.
3. Wide range from thin to thick
The same paint can be used as a thin wash, a smooth opaque layer or thick impasto with visible brush marks. This range gave painters enormous expressive freedom, from the smooth surfaces of Renaissance portraits to the textured brushwork of later painters.
4. Rich, saturated color
Pigments bound in oil often look deeper and more saturated than in water-based media, because the oil has a refractive index that makes many pigments appear richer. Colors also change little in value between wet and dry, unlike some water-based paints.
5. Flexibility suited to canvas
Dried oil paint remains somewhat flexible, especially when applied in properly structured layers. That made it compatible with stretched canvas, which could be rolled, shipped and made in much larger sizes than heavy wooden panels.
6. Durability
Well-made oil paintings can last for centuries. The cured film is tough and water-resistant. Varnishes add further protection and can be removed and replaced during conservation, extending a painting’s life.
7. Realism and the illusion of light
The combination of blending, glazing and saturated color made oil ideal for convincing illusions of light, texture and space. As Western painting moved toward naturalism, oil was the medium that delivered it most effectively.
The History in Brief
Refinement in the 15th century
Oil had been used in painting before the 15th century, but painters in the Low Countries refined it into a sophisticated technique around that time. Jan van Eyck is often credited with popularizing it, though historians generally agree he did not invent oil paint. His work demonstrated what layered oil could achieve.
Spread to Italy
Italian painters adopted and adapted oil during the later 15th century. Venice was especially important: its humid climate was hard on frescoes, and its painters embraced oil on canvas, developing looser, more atmospheric handling.
Canvas replaces panel
By the 16th century, canvas had become common for easel paintings. Canvas was lighter, cheaper and easier to transport than wooden panels, and it allowed large paintings that could still be moved. Oil’s flexibility made this shift possible.
Paint tubes and painting outdoors
In 1841, the American painter John Goffe Rand patented a collapsible metal paint tube. Before then, painters or assistants ground pigments and stored paint in pig bladders or other containers that were awkward to transport. Tubes made oil paint portable and convenient, helping fuel painting outdoors in the 19th century.
How Oil Painting Mediums Extend These Strengths
Part of oil paint’s dominance comes from how adjustable it is. Painters add mediums to change drying time, flow, gloss and transparency.
Is oil painting a medium?
The word “medium” has two meanings in painting. It can mean the type of paint, so oil painting is a medium, just as watercolor and acrylic are. It also refers to the liquids added to paint to modify it. In oil painting, those mediums include oils, solvents and resins.
Common oil painting mediums
| Medium | What it does | Typical use |
|---|---|---|
| Linseed oil | Increases flow and gloss; slows drying slightly | General-purpose medium, upper layers |
| Stand oil | Thicker, polymerized linseed; levels brush marks, glossy | Glazing, enamel-like finishes |
| Walnut or safflower oil | Paler oils that yellow less | Whites and light colors |
| Alkyd mediums | Speed drying significantly | Faster layering, glazing |
| Odorless mineral spirits or turpentine | Thin paint and speed early drying | Underpainting, lean early layers |
| Glazing medium | Increases transparency while keeping body | Transparent color layers |
How to use oil painting medium safely and effectively
- Follow fat over lean. Early layers should have less oil (more solvent), later layers more oil. This helps upper layers stay flexible and reduces cracking.
- Add mediums in small amounts. Too much oil can cause wrinkling or yellowing; too much solvent can make paint underbound.
- Glaze over dry layers. Apply thin, transparent mixes over paint that is dry to the touch.
- Ventilate. Solvent-based mediums release fumes; use good airflow and keep containers closed.
- Dispose of rags safely. Oil-soaked rags can self-heat; lay them flat to dry or store them in a sealed metal container with water before disposal.
What is the best oil painting medium?
There is no single best medium; it depends on the effect. Many painters start with a simple mix of linseed oil and odorless mineral spirits, adjusting the ratio as layers progress. Those who want faster drying often use an alkyd medium, and painters focused on glazing may prefer a stand oil blend.
The Role of the Easel Itself
Oil painting and the easel grew up together. Oils are typically painted upright, because thick paint stays in place and the painter can view the work as it will hang. Studio easels evolved to hold canvases of increasing size securely at adjustable heights and angles.
Large, heavy canvases need sturdy easels, while painting outdoors needs portable ones. That relationship continues today, and choosing an easel that matches the size and weight of your canvases makes oil painting more comfortable. Heavier H-frame studio easels suit large canvases, while lighter field easels and pochade boxes suit painting on location.
Does Oil Still Dominate Today?
Oil remains widely respected and used, especially for gallery painting and portraiture. But since the mid-20th century, acrylic has become a major alternative. Acrylic dries fast, cleans up with water and avoids solvents, which suits many modern painters and classrooms.
Water-mixable oils offer a middle ground, behaving much like traditional oils while cleaning up with water. Many artists choose based on working style: oil for slow blending and luminous layering, acrylic for speed and convenience.
Oil vs Acrylic for Easel Painting
| Feature | Oil | Acrylic |
|---|---|---|
| Drying time | Days to weeks | Minutes to hours |
| Blending | Long working time, easy wet blending | Shorter working time; retarders help |
| Color shift when dry | Minimal | Often darkens slightly |
| Cleanup | Solvents or oil and soap | Water while wet |
| Track record | Centuries | Decades |
| Layering rules | Fat over lean | Few restrictions |
FAQs
Why is oil paint used for easel painting?
It dries slowly for blending, supports both glazes and thick paint, produces rich color, stays flexible on canvas and lasts for centuries. These traits suit portable, highly finished paintings.
Who invented oil painting?
No single person invented it. Oil was used earlier, but 15th-century painters in the Low Countries, including Jan van Eyck, refined and popularized the technique for panel painting.
Is oil painting a medium?
Yes, in one sense: it is a type of paint, like watercolor or acrylic. “Medium” also refers to additives such as linseed oil or solvents that change how oil paint behaves.
What is the best medium for oil painting beginners?
A simple mix of linseed oil and odorless mineral spirits is a common start. Use more solvent in early layers and more oil in later layers, following the fat over lean principle.
Why did canvas replace wooden panels?
Canvas is lighter, cheaper, easier to transport and available in large sizes. Oil paint’s flexibility made it suitable for canvas in a way brittle tempera was not.
How do you use glazing medium in oil painting?
Mix a small amount with transparent paint and apply thin layers over a dry underpainting. Each glaze modifies the color beneath, building depth and luminosity.
Final Thoughts
Oil rose to dominance because it offered painters what earlier media could not: time to blend, the ability to glaze, a full range of textures, rich color, flexibility on canvas and lasting durability. Paired with portable canvas and later paint tubes, it became the natural choice for easel painting for more than five centuries.
If you are working in oils yourself, a steady, adjustable easel makes those long, layered sessions easier. Explore our roundup of sturdy easels for oil painters to find a studio or field model suited to your canvas sizes.
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