Oil painting is a wonderful medium all on its own, but there are modifiers that you can add to the oil paint that can change its behavior. This article will give you an overview of some of the more popular oil painting mediums available to today's oil painters. The use of oil painting mediums is really a matter of taste and not a requirement. Many artists do not use any mediums at all other then a bit of oil to make the paint more workable, as some paints are quite thick straight from the tube. Other artists swear by certain mediums. It should also be noted that artists differ on opinion when it comes to the effectiveness and quality of oil painting mediums, so you should experiment on your own and form your own opinion. Make sure before using any oil painting medium that you read all warning labels and always work in a well ventilated area. It is also recommended that you work with gloves to protect your skin.
Linseed oil is made from the seed of the flax plant. During its early history, linseed oil had a different role then it has today. Originally it was used as a final varnish for paintings that were created using the egg tempera medium. Linseed oil is used as binder in today's oil paints. Linseed oil dries thoroughly and forms a strong paint film. Because linseed oil dries slowly, the paint remains in a workable state, enabling the artist to continue working on the painting for some time. When linseed oil ages, it does tend to yellow unfortunately. Many painters avoid using linseed oil with lighter colors like whites and yellows. Below are a few varieties of linseed oils that are available to today's oil painters.
COLD PRESSED LINSEED OIL
Cold pressed linseed oil is made by extracting the oils from the raw flaxseed. The oil is extracted by using pressure and not heat, thereby creating a linseed oil in its purist form. Cold pressed linseed oil can be used as a binder in oil paints, but can also be used as a medium to thin oil paints, heighten gloss and transparency, and reduce the visibility of brush strokes. Many painters and manufacturers alike feel cold pressed linseed oil is superior in quality to other linseed oils because there is no refinement made to the oil. Cold pressed linseed oil results in a low yield, so this oil does carry a heftier price tag.
STEAM PRESSED OR REFINED LINSEED OIL
When the flaxseed is steam heated and then pressed it yields more oil, thereby making refined linseed oil a more affordable medium for artists and for use as a binder in oil paints. The process of steam heating the flax seeds produces more waste, so this waste has to be removed through a refinement process. The oil is treated with an acid which removes the waste materials. The acid is then neutralized with an alkali solution. Refined linseed oil can be used to thin oil paint and increase brilliance and transparency.
SUN THICKENED LINSEED OIL
Sun thickened linseed oil is a thick bodied medium that is produced using the heat of the sun. An equal amount of both linseed oil and water are mixed together in a container and left in sunlight for several weeks or longer. The water and linseed oil eventually separate resulting in a thicker oil with a honey like consistency. Sun thickened linseed oil is not used as a binder in oil paints but as an independent medium that improves flow and increases gloss. Sun thickened linseed oil has less of a tendency to yellow and speeds drying.
Stand oil is also a thick bodied medium like sun thickened linseed oil. Linseed oil is heated at a high steady temperature, in an air tight container, which results in a very thick honey like consistency. Stand oil is useful as a glazing medium when mixed with turpentine and damar varnish. Stand oil helps improve the flow and has good resistance to yellowing. Stand oil is a slow drying medium that produces a strong enamel like paint film.
POPPY SEED OIL
Because linseed oil has a tendency to yellow as it ages, other oils have come onto the market. Amongst these oils are poppy seed and safflower oil. Poppy seed oil is extracted from the seeds of the opium poppy. Poppy seed oil is a pale slower drying oil and is less likely to yellow when compared with linseed oil. It is often used with whites, blues and pale colors.
Safflower oil is similar to poppy seed oil in that they both are suitable for whites and light colors. It has less of a tendency to yellow when compared to linseed oil.
Walnut oil is a pale oil that helps make paint more fluid and has good drying power. It has less of a tendency to yellow when compared with linseed oil. Walnut oil has to be stored properly or it can spoil.
Liquin is a popular oil painting medium. Many artists swear by it and it is definitely worth a try if you have never worked with it before. Liquin improves the flow of oil and alkyd colors and helps in subtle blending and fine detail. It speeds drying and serves as a good medium for glazing.