Oil paint is essentially one or more pigments combined with a binder (the oil) and a thinner (such as turpentine). The oil functions as a carrier to hold and apply the pigments, while the thinner makes the paints easier to apply to surfaces with a brush. Linseed oil is the most popular oil in these artistic paints because it dries faster and provides more flexibility than other oils, such as walnut or safflower.
Oil paints take longer to dry than other paints, such as watercolors. This provides more time for artists to work with their creations and make changes.
Advantage: Color Depth and Range
Oil paints provide for a wide range of colors and a rich color depth, as they can be layered and mixed more freely than other paints, such as watercolor or acrylics. Artists can subtly change the richness and tone of their colors by adding minute amounts of other colors, for instance. This is partially true because oil paints take longer to dry.
Advantage: Varied Applications
Oil paints can be applied to surfaces in a greater variety of ways than other paints. Oil paints can be made into thin glazes or thick impastos, according to the Encyclopedia of Irish and World Art: 2010.
Advantage: Range of Finishes and Effects
Oil paints can be mixed to appear opaque, transparent or anything in between, as well as have a matte or gloss finish or anything in between.
Oil paints do not noticeably change in color, texture or finish once dried. This makes it easier for artists to predict what the finished creation will look like compared to other paints (such as watercolors) that can change their appearance after drying.
Disadvantage: Drying Time
The slow drying time of oil paints can be a disadvantage to some artists, especially those who purposely work with a dry underpainting or like to use a sequence of washes in quick succession.
Disadvantage: Lack of Clarity
Because oil paints can be painted over once dried—thus, essentially, correcting many mistakes—some artists have trouble focusing on a clear vision, intention or expression, according to the Notebook website. These artists may be better off using paints that force decisions.
Disadvantage: Blending Capabilities
Oil paints blend easily with one another, which can encourage certain artists to just keep blending until the colors and shapes become muddy or unclear. Once muddied, it is difficult to "unmuddy" oil paint colors.
Disadvantage: Aging Process
Linseed oil paints—the most popular variety—tend to darken or yellow with age. While this can be combated with certain application techniques and quality materials, these are not necessarily able to be used or accessible to every oil painter.