Fundamentals of Oil Painting Techniques Explained

Saint Barbara
Jan van Eyck, Public domain, via Wikimedia Commons

Master the Canvas

Oil painting has been the medium of choice for the world’s most iconic masterpieces for centuries. From the luminous skin tones of the Renaissance to the thick, expressive swirls of Post-Impressionism, the versatility of oil paint is unmatched. 

Its slow drying time allows for endless blending, while its chemical nature permits both transparent glazes and heavy, sculptural applications.

If you are looking to start your journey into this "Old Master" medium, understanding the core fundamentals is essential. 

In this article, we will explore the primary techniques of oil painting by looking at how history’s greatest artists utilized them.

1. Underpainting and Imprimatura: The Skeleton of the Work

Before a master artist ever applied a final color, they established the "bones" of the painting. This is typically done through Imprimatura (a thin, transparent stain of color) and Underpainting (a monochromatic version of the final image).

The goal is to eliminate the intimidating "white" of the canvas and establish the values—the relationship between light and dark. By mapping out the shadows first, the artist ensures the final composition has depth.

Case Study: Johannes Vermeer

Vermeer was a master of light, but that light was built upon a rigorous underpainting. In many of his works, he used an "earth-tone" underpainting to establish where the light from a window would fall. This technique allowed him to focus purely on form before worrying about the complexities of local color.

In The Art of Painting, you can see the incredible depth achieved. By using a dark underpainting for the checkered floor and the heavy tapestry on the left, Vermeer created a "base" that makes the final highlights pop with photographic realism.

2. Fat Over Lean: The Golden Rule of Longevity

If there is one technical rule you must follow, it is Fat Over Lean. This refers to the chemical buildup of the paint layers.

• Lean Paint: Paint mixed with more solvent (like turpentine or mineral spirits). It dries quickly.

• Fat Paint: Paint mixed with more oil (like linseed or poppy oil). It dries slowly and remains flexible.

To prevent the painting from cracking, you must apply "fat" layers over "lean" layers. If a fast-drying (lean) layer is placed on top of a slow-drying (fat) layer, the top layer will crack as the bottom layer continues to shift and dry underneath it.

3. Chiaroscuro and Tenebrism: The Drama of Light

Chiaroscuro (Italian for "light-dark") is the use of strong contrasts between light and dark to give the illusion of three-dimensional volume. When this contrast is taken to an extreme, it is called Tenebrism, where the background is almost entirely black, and the subject is "spotlit."

Case Study: Caravaggio

Caravaggio is the undisputed king of Tenebrism. He used oils to create intense, theatrical scenes that felt like they were emerging from deep shadows.

In The Calling of St Matthew, notice how the light enters from the top right, slicing through the darkness. The oil medium allows for those incredibly smooth transitions (sfumato) from the brightly lit faces into the void of the background. This technique directs the viewer's eye exactly where the artist wants it to go.

4. Glazing and Scumbling: The Secret to Luminous Skin

One of the greatest advantages of oil paint is its transparency.

• Glazing: Applying a thin, transparent layer of "fat" paint over a dry, lighter layer. This acts like a sheet of colored glass, changing the tone without hiding the details beneath.

• Scumbling: Applying a thin, opaque, "dry" layer of light paint over a darker area. This creates a hazy, atmospheric effect.

Case Study: Titian

The Venetian master Titian was famous for his "thirty or forty glazes." He would build up skin tones using layers of transparent reds and yellows over a cool underpainting, which gave his figures a lifelike, "breathing" quality.

Self-Portrait
Rembrandt, Public domain, via Wikimedia Commons

5. Impasto: Adding Physical Texture

While glazing is about thinness, Impasto is about thickness. It involves applying paint so thickly that it stands out from the surface, showing the visible strokes of the brush or palette knife. This technique is used to catch actual physical light on the ridges of the paint.

Case Study: Vincent van Gogh

Van Gogh moved away from the smooth, blended traditions of the past and embraced the raw energy of the medium.

In The Starry Night, the stars aren't just represented by color; they are physical swirls of paint. By using the impasto technique, Van Gogh added a sense of movement and emotion that flat painting could never achieve. The oil paint holds the shape of his brush perfectly, frozen in time.

6. Alla Prima: The "Wet-on-Wet" Method

Most classical masters worked in layers (indirect painting). However, Alla Prima (Italian for "at first attempt") is a technique where the painting is finished in one sitting, while the paint is still wet. This is also known as "wet-on-wet."

This requires a high level of confidence, as you are blending colors directly on the canvas rather than layering them over dry paint. It is the hallmark of many Impressionist and Plein Air (outdoor) painters.

Summary Table of Techniques

Technique	Description	Best For
Imprimatura	Initial thin stain of color on canvas	Eliminating white space
Fat Over Lean	Layering flexible paint over stiff paint	Preventing cracks
Chiaroscuro	Strong contrast of light and dark	Creating 3D volume
Glazing	Thin, transparent layers	Luminous skin/depth
Impasto	Thick, textural application	Expression and highlights
Alla Prima	Painting wet-on-wet in one session	Speed and energy

Conclusion

Oil painting is a dialogue between the artist and the medium. Whether you prefer the calculated, glowing layers of Vermeer or the frantic, textured energy of Van Gogh, these fundamental techniques remain the same. By mastering Fat Over Lean, experimenting with Glazing, and understanding the power of Chiaroscuro, you can unlock the full potential of the canvas.