What is a paint medium?
A paint medium is essentially a substance that is added to paint to alter its properties, such as the way the colour appears and behaves - allowing you to customise your paint to perform in the desired way. There are a variety of reasons why you may need to reach for a medium when working with oil paints - this could be for altering drying time, changing the sheen, the texture or how transparent it is.
What are the main aims of an oil painting medium?
Oil painting mediums main aims are to alter viscosity, surface finish or drying time of oil paint, and through this, you can achieve a variety of sheens and either extend or shorten the drying time of the paint. You can either mix them directly with the paint on your palette or dip them into your brush into them as you would water.
The key to controlling your paint, is knowing when and how to use your medium - this will allow you to build upon and improve your technique as an artist. When mixing your oil mediums, it's important to bear in mind that most oil mediums are naturally tinted slightly yellow, so we would recommend paying close attention when mixing them with lighter colours.
Linseed Oil, particularly refined Linseed oil is the most popular form of oil painting medium. Using refined linseed oil will slow the drying time of the paint, which is very helpful when painting in layers. We recommend the Winsor & Newton Refined Linseed Oil, which is a low viscosity alkali refined oil of pale colour that dries slowly. Its features include reducing oil colour consistency, increasing gloss and transparency as well as adding to other oils for slower drying. When using this, a top tip would be to paint your fast-drying layers first, and then each layer on top should take longer to dry than the previous one. You can therefore apply more of this medium with each layer.
If you are concerned about yellowing, try the Old Holland Stand Oil, which is a boiled, polymerised linseed oil that increases fluidity and makes it possible to remove brush strokes. It also will increase the glossiness of the painting and lengthen the drying time.
The Winsor & Newton Liquin Original is one of our top picks as a great general purpose semi gloss medium that helps speed the drying process, improves flow and reduces brush stroke retention. This medium actually halves the drying time of conventional oil colour as well as resisting yellowing. Or try the Winsor & Newton Liquin Oleopasto for a semi-matt, quick drying and non-yellowing impasto medium which adds body and helps level slightly. This medium also thickens rapidly and has the ability to extend tube colour.
Some mediums contain a variety of different chemicals, such as the Old Holland Oil Painting Medium Quick Drying, which is made of a mixture of linseed oil, turpentine oil and white spirit. This medium is best for oil painters who want to speed up the drying process as this medium will speed up the drying time, as well as reducing the glossiness of the painting. It is also important to note that with this medium the brushstrokes will remain visible. For a medium with similar properties but doesn't have any effect on drying time, try the Old Holland Oil Painting Medium as a way to dilute the oil paint and increasing fluidity.
Using Turpentine as a medium
Technically, turpentine would fall under the category of solvents, but can be used as a medium for oil painting as a way to dilute paint. This traditional solvent has been used for centuries to dilute paint! When mixed with a little pigment to a thin wash, it provides a fast-drying colour that's perfect for underpainting or creating the general outlines of the composition. If you are going to explore turpentine as a medium, be sure to check out our blog on solvents to ensure you are using it safely due to the harsh fumes it possesses and to ensure this is the right choice of medium for you!
Low Odour Thinners/White Spirit
Another medium that technically falls under the solvents category are low odour thinners/white spirit. Turpentine, white spirit or low odour thinners or mineral spirits are often easily confused, but the difference essentially boils down to where the chemicals are derived from. Turpentine is derived from natural resins extracted from trees, whereas white spirit and low odour thinners are petroleum-based. Low odour thinners have the same quick-drying properties as turpentine or white spirit, and if you want to speed up the drying process you can mix with linseed oil. We would recommend trying Winsor & Newton Sansodor Low Odour Solvent as a more gentle alternative to white spirits, which you can learn more about here.
If you have any further questions on oil painting mediums or simply fancy a chat, feel free to pop in to see our friendly in-store team or drop us a email at firstname.lastname@example.org.