Acrylic Painting
Course

Oil painting is the process of painting with pigments with a medium of drying oil as the binder. Commonly used drying oils include linseed oil, poppy seed oil, walnut oil, and safflower oil. 

The choice of oil imparts a range of properties to the oil paint, such as the amount of yellowing or drying time. Certain differences, depending on the oil, are also visible in the sheen of the paints. 

An artist might use several different oils in the same painting depending on specific pigments and effects desired. The paints themselves also develop a particular consistency depending on the medium. The oil may be boiled with a resin, such as pine resin or frankincense, to create a varnish prized for its body and gloss.

The oldest known oil paintings were created by Buddhist artists in Afghanistan and date back to the 7th century AD.^[1] The technique of binding pigments in oil was known in Europe by at least the 12th century. 

The adoption of oil paint by Europeans began with Early Netherlandish painting in Northern Europe, and by the height of the Renaissance, oil painting techniques had almost completely replaced the use of tempera paints in the majority of Europe.

In recent years, water miscible oil paint has become available. Water-soluble paints are either engineered or an emulsifier has been added that allows them to be thinned with water rather than paint thinner, and allows, when sufficiently diluted, very fast drying times (1–3 days) when compared with traditional oils (1–3 weeks).

Techniques

A basic rule of oil paint application is ‘fat over lean‘, meaning that each additional layer of paint should contain more oil than the layer below to allow proper drying. If each additional layer contains less oil, the final painting will crack and peel. 

This rule does not ensure permanence; it is the quality and type of oil that leads to a strong and stable paint film.

There are other media that can be used with the oil, including cold wax, resins, and varnishes. These additional media can aid the painter in adjusting the translucency of the paint, the sheen of the paint, the density or ‘body’ of the paint, and the ability of the paint to hold or conceal the brushstroke. 

These aspects of the paint are closely related to the expressive capacity of oil paint.

Traditionally, paint was most often transferred to the painting surface using paintbrushes, but there are other methods, including using palette knives and rags. 

Oil paint remains wet longer than many other types of artists’ materials, enabling the artist to change the color, texture or form of the figure. At times, the painter might even remove an entire layer of paint and begin anew. T

his can be done with a rag and some turpentine for a time while the paint is wet, but after a while the hardened layer must be scraped off. Oil paint dries by oxidation, not evaporation, and is usually dry to the touch within a span of two weeks (some colors dry within days).

 It is generally dry enough to be varnished in six months to a year