Bill Martin's Guide to Oil Painting
Clean Up As Soon As You're Finished
Because oil paints take a long time to dry they can get on everything and once they've dried they're hard to remove. Brush handles, painting knives and paint tubes are the most common sources of contamination. To minimize this it is a good policy to clean any excess paint from these surfaces immediately using your citrus thinner. If you have the paint on yourself clean it immediately with citrus thinner also. This is followed by soap and water. If it gets on your clothes clean it as best you can with the thinner and then wash the clothes the same day.
Brushes should be cleaned between colors and at the end of each painting session. First wipe off any excess paint on the hair or handle with a rag. Then swish the brush in citrus thinner until all color is gone. Dry the brush with a clean rag.
At the end of a painting session clean all the brushes you used with citrus thinner. Wipe them dry. Then clean them again with soap and water until the foam from the soap is white. Rinse out the soap with clear water. Shape the wet brush and set it on a flat surface with the bristles beyond the edge. Let them dry overnight. (Fels-Naptha soap is very effective for removing the staining colors of oil paint.)
Colors should not be allowed to dry on your palette. To clean your palette first scrape off as much color as possible with your palette knife and put it in a can for future disposal. Then wipe the palette with a dry paper towel or rag followed by one moistened with citrus thinner. Then wipe dry.
Your Palette Knives
Palette knives are used to mix the colors together. Once the color is mixed the knife is wiped clean. Thinner is usually not necessary.