Oil paint is made using two main ingredients: pigments and oil. The particles of pigment are suspended in the drying oil, which forms a film when exposed to air. The most commonly used oils are walnut oil, linseed oil, safflower oil and poppyseed oil. Using different oils to make oil paint results in different finishes to the painting, and a varying drying time.
Many artists favour oil paint over paints such as acrylic paint because of its finish, drying time, versatility and durability. Some recommend oil painting for beginners as it’s easy to work with, although perhaps not as easy as acrylic paint.
Oil paints are often more muted in colour than acrylics, and are widely regarded as the medium that gives the most realistic finishes to a painting. There’s something about the way oil paint captures the fine details and finishes that is difficult to accomplish with acrylic paint. Vincent Van Gogh, ‘the painter of sunflowers’, produced over 860 oil paintings in his short lifetime.
Oil painting is also favoured by many because it takes a much longer time to dry than other paints, meaning that the artist has more time to correct mistakes and add details while the paint is still drying, an added bonus for oil painting for beginners.
The versatility of oil paints is also a huge advantage over other paints. With a linseed oil painting, for example, paint can be applied with brushes or palette knives and with differing pressures to give different results. Oil paints blend easily and are able to make very subtle variations in colour that result in the overall realism of a piece.
Oil paints are incredibly durable and, although the oil in them can degrade over a period of years, this can be mitigated by re-coating the painting with a thin layer of the oil that was used in the paint. The natural ingredients in the vegetable oils used in oil paint decompose naturally, leaving no waste residue. In 1888 Paul Gauguin, a friend of Vincent Van Gogh’s, painted a portrait of him entitled ‘the painter of sunflowers’ which is one of many oil paintings from the 19th century to have stood the test of time.
The main disadvantage of using oil painting, for beginners, is their cost. Good quality oil paints tend to be much more expensive than other paints, such as acrylic and latex paint, due to the manufacturing process and their contents. Like other paints, the quality of the pigments used will also affect the cost of the paint.
Linseed oil is the most commonly used oil in the process of making oil paints. It is extracted from the seeds of the flax plant using a method known as cold pressing. The raw oil separates over a period of about 6 months, leaving a pure oil behind.
The surface tension of this oil is much lower than water, meaning that the oil can penetrate the substance it is on deeply. It’s this quality that means that a linseed oil painting has a very high durability.
Linseed oil comes in three types: stand oil, sun-bleached oil and sun-thickened oil, each with their own thickness and drying time. This drying oil is known for leaving a yellow tint on paintings, which means that other artists enjoy using oil paints made from alternative vegetable oils.
Poppyseed oil is extracted from poppyseeds, and is a great alternative to linseed oil painting. It does not leave as strong a yellow tint as linseed oil because of its lightweight nature.
Poppyseed oil is often used in white oil paint, light colours and blue tones, but dries slower than linseed oil paints. Although additives can be used to decrease the drying time, artists using poppyseed oil paints should be aware that a couple of weeks may be needed for the painting to dry down completely.
Walnut oil is extracted from walnuts, and is another popular oil for making oil paints. Like poppyseed oil, it has a much-reduced yellow tint, which makes it ideal for painting with lighter colours, and takes longer to dry.
Walnut oil was the most common oil used by Renaissance painters, and today is often used as a brush cleaner and paint thinner.
Safflower oil is extracted from the seeds of safflower plants. It’s the palest of the drying oils used in oil paints, making it ideal for use with white colours. It is similar in its characteristics to poppyseed oil, except that it dries faster.
How Oil Paint Is Made
Oil paint is made by suspending pigments in a drying oil from the list above. Drying oil absorbs oxygen, meaning that over time the liquid is changed into a hard coating. The ideal drying oil is paler in colour, has a short drying time and is pure, with no impurities.
Only a small amount of drying oil is often needed to make a great oil paint, meaning that the percentage of pigment in the paint is much higher than other paints.
1. Oil is measured
The first step in the oil paint-making process is to measure the quantity of oil into separate, heavy-duty containers. Stainless steel is easy to clean keep to prevent cross-contamination of pigments.
2. Stearate is added
Stearate is a wax-like solid that is added to the oil in order to increase the stability of the paint. These two substances are thoroughly mixed before any pigment is added.
3. Pigment is added
Next, the pigment is measured and added slowly to the oil. The pigment needs to be added gradually to the oil so that it can be thoroughly mixed.
4. Slow mixing
Next, the mixture is mechanically mixed for a few hours, as the dry pigment is gradually incorporated into the oil mixture.
5. Triple-roll milling
A triple-roll mill is essentially three horizontal granite rollers that each run at different speeds and spin in alternating directions. The oil paint paste is fed through the rollers in an effort to further separate and distribute the pigments in the paint. The paste is fed through the machine multiple times, depending on which pigments have been used, and the size of the particles.
Once the paint-maker is satisfied with the appearance of the paint, it is tested using a precisely honed stainless-stell gauge to check that the pigments are dispersed evenly.
|Drying Time||Yellow Tint||Suitable Colours|
|Linseed Oil||3-5 days||Strong||Most, darker|
|Poppyseed Oil||5-7 days||Moderate||Light, blue-toned|
|Walnut Oil||4-6 days||Moderate||White, light|
|Safflower Oil||4-6 days||Least||White|