How to oil paint

Overview

Oil painting is a versatile and historically significant artistic technique that utilizes pigments suspended in a drying oil, most commonly linseed oil. This medium allows for rich colors, subtle blending, and a wide range of textural effects. Its slow drying time provides artists with extended periods to work on their pieces, making it ideal for detailed rendering and smooth transitions. Mastering oil painting involves understanding the properties of the paints, the tools required, and essential techniques such as layering, blending, and proper brush care.

Materials for Oil Painting

Before you begin, gather the necessary supplies:

• Oil Paints: Available in tubes, these consist of pigment mixed with a binder (oil). Common colors include Titanium White, Cadmium Yellow, Alizarin Crimson, Ultramarine Blue, and Burnt Umber.
• Brushes: Hog bristle brushes are good for thicker paint and texture, while synthetic or sable brushes are better for smoother application and detail. A variety of shapes and sizes (flat, round, filbert) is recommended.
• Palette: A surface to mix your paints on. Options include wooden palettes, glass palettes, or disposable palette paper.
• Mediums and Solvents:
  • Solvents: Turpentine or odorless mineral spirits are used to thin the paint for the initial layers (lean layers) and for cleaning brushes.
  • Mediums: These are liquids added to the paint to alter its consistency, drying time, and sheen. Common mediums include linseed oil, stand oil, or alkyd mediums.
• Surface: Most commonly canvas (stretched or on board), but wood panels, paper, or metal can also be used. Ensure the surface is properly primed with gesso to prevent the oil from damaging it.
• Palette Knives: Useful for mixing paint and applying it thickly (impasto).
• Easel: To hold your surface upright while you paint.
• Rags or Paper Towels: For wiping brushes and cleaning up spills.

Getting Started: The Basic Process

The fundamental approach to oil painting involves applying paint to a primed surface, often starting with thinner layers and gradually building up to thicker ones.

1. Preparing Your Surface

Most surfaces, especially raw canvas or wood, need to be primed. Gesso, an acrylic primer, is commonly used. Apply 2-3 thin coats, sanding lightly between coats for a smoother finish if desired. This seals the surface and provides a good base for the paint.

2. Setting Up Your Palette

Squeeze out small amounts of the colors you intend to use onto your palette. Avoid squeezing out too much, as oil paints have a long working time and can become gummy if left out too long. Arrange colors logically, perhaps with whites and lighter colors on one side and darker colors on the other.

3. The "Fat Over Lean" Rule

This is a cornerstone of oil painting technique. It refers to the oil content in your paint layers. "Lean" layers have less oil (more solvent), while "fat" layers have more oil (less solvent or added oil medium). The rule states:

• Start with lean layers: Use paint thinned with solvent for your initial sketch or underpainting. This layer dries faster and provides a stable base.
• Gradually increase the oil content: Subsequent layers should have progressively more oil. The final layers can be applied directly from the tube or mixed with oil mediums.

Violating this rule can cause the paint to crack as it dries, because the upper, oil-rich layers expand more than the lower, lean layers.

4. Applying Paint

Underpainting: Many artists begin with an underpainting, often in a monochromatic color (like burnt sienna or raw umber), to establish the composition, values, and basic forms. This can be done with thin, diluted paint.

Layering: Build up your painting by applying subsequent layers. You can use brushes for smooth application or palette knives for thick, textured strokes (impasto). Blend colors directly on the canvas or on your palette.

Glazing: A technique where thin, transparent layers of color are applied over an existing dry layer. This creates luminous effects and subtle color shifts. Glazes are typically made with a lot of medium and very little pigment.

5. Drying Times

Oil paints dry through oxidation, a slow chemical process. Thin layers might dry to the touch in a day or two, but thicker applications can take weeks or even months to cure fully. Alkyd mediums can significantly speed up drying times.

6. Cleaning Your Brushes

Thorough brush cleaning is essential for maintaining your tools. After painting:

1. Wipe off excess paint with a rag.
2. Dip the brush in solvent (turpentine or mineral spirits) and work the paint out.
3. Repeat with clean solvent until most of the color is gone.
4. Wash the brushes with soap and water (artist's brush soap is ideal).
5. Rinse thoroughly and shape the bristles. Let them dry flat or bristle-end up.

Never leave brushes soaking in solvent, as it can damage the bristles and ferrule.

Advanced Techniques and Considerations

Scumbling: Applying a broken layer of opaque or semi-opaque paint over another layer so that patches of the underlayer show through. This is often done with a dry brush.

Alla Prima (Wet-on-Wet): Completing a painting in a single session while the paint is still wet. This requires quick work and decisive strokes, often involving blending colors directly on the canvas.

Varnishing: Once the painting is completely dry (which can take 6-12 months), applying a final varnish protects the surface from dust and UV light and evens out the sheen. Removable varnishes are recommended.

Ventilation: Always paint in a well-ventilated area, especially when using solvents like turpentine, as the fumes can be harmful.

Oil painting offers a lifetime of learning and exploration. Experiment with different materials, techniques, and subjects to develop your unique style.