Some artists would not paint without an oil painting medium. Others don't use a medium at all. A medium is a substance that holds and carries pigment in your paint. Tube oil paints already have a medium mixed with pigment. The amount of medium can vary greatly according to brand. When there is too much medium mixed with the pure pigment, there can be a loss of vibrancy in colour. On the other hand, adding a little medium to your oil paint can help to spread or blend the colour more easily, especially if the tube paint is very thick.
Mix one part linseed stand oil with two parts turpentine or odourless white spirit. You will find that these two liquids won't mix readily. Linseed oil can be very thick and slow drying depending on the temperature and humidity that you are painting in. You can substitute sun-thickened linseed oil for the linseed stand oil in order to save a few extra days during your painting's drying period. However, sun-thickened linseed oil may cause the lighter oil colours you are using to turn slightly yellow over time.
Cover tightly. Use a glass container with a screw cap to get a tight seal.
Let it sit. You may need to wait several days for the linseed stand oil and the turpentine or white spirit to mix completely. Turning your glass container on its side or top several times a day will help the liquids mix together more quickly.
Pour a small amount into another container after the linseed stand oil and turpentine or white spirit have thoroughly mixed together. You are now ready to dip your brush in your oil painting medium and begin your new masterpiece. Be sure your container has a tight fitting lid in order to save any mixture that may be left over after your painting session. You can purchase oil painting medium at any art supply store. However, making your own is a wonderful part of the art process and will probably save you more than a few dollars.
Linseed stand oil and turpentine can both be found at your local art supply store. This oil painting medium will help make your oil paint more durable. There will also be less tendency of the paint to crack as it dries. Other oils can be used to make oil painting mediums. Poppy seed oil and walnut oil are options. They have faster drying times but tend to have a yellowing effect on the oil paints over time.