Oil paints are made by grinding pigments with a drying or semi-drying vegetable oil such as linseed, safflower or poppy seed oil. The oil binding medium is responsible for the appearance and buttery feel of the paint. It also acts as an adhesive to attach the pigments to the painting surface.
Pigment particles do not have the same smooth shape or size. If they did then they would all need the same amount of oil to coat their surfaces. To reach a desired uniform consistency each pigment needs a specific amount of oil.
We discussed “fat-over-lean” in yesterdays blog. Paint with less oil content is not as flexible and if you paint it over a color with high oil absorption it could crack in time.
An artist painting with oil paint should understand and know the content of oil in their pigments. Here are some examples:
High oil content (70%or more)
- Burnt Sienna
- Raw Sienna
- Burnt Umber
- Winsor Blue
- Green Alzirin
- Permanent Rose
- Cobalt
Medium oil content: (50% to 70%)
- Cadmium Yellow
- Cadmium Red
- Raw Umber
- Oxide of Chromium
- Ivory Black
Low Oil Content: (50% or less)
- Ultramarine
- Manganese Blue
- Flake White
These are the pigments that belong in the particular categories listed. There may be others that belong in these categories. Check information when purchasing your paints.
