Painting with oil-based paints has long been regarded as the provenance of
traditional or classical fine arts. Oil paint, once difficult to use, required
extensive knowledge of chemicals and minerals. Now oil paint is ready to
use from the tube and, with specific additives, is easy to apply. For extended
study on classic oil painters, review the work of John Singer Sargent and
Oil-based pigments are pigments ground in an oil base. Oil-based pigments
are available in tubes, cans, and pressurized cans. Oil-based pigments in
tube form are generally what we know as oil paint. This section on oil-based
pigment will also briefly cover lacquer and enamel paints.
Oil paints are pigments ground in linseed oil. The most pure color is
attainable straight from the tube. Impressionist painters, obsessed with purity
and light, often used paint from the tube without additives. Today, oil
painters use additives to extend the pigment, change consistency, and
increase or reduce drying time. Oil paint requires a finishing treatment when
the painting is complete.
An extender slightly increases the mass of pigment without changing its hue.
An extender thins the viscosity of the paint giving it the consistency of melted
butter. Use an extender in oil paint when you want to create a glaze or to
apply transparent color over the surface of the painting. This technique is
referred to as stumbling.
An impasto is a paste or putty additive to oil to create a heavier bodied
pigment. An impasto increases the mass and viscosity of pigments without
changing its hue. Use an impasto when you want to thickly build up pigment
on the painting surface and for textural effects.
Reducers are chemical additives that reduce the drying time of oil paint.
Reducers do not affect hue, but they will thin pigment consistency. The
more reducer added to paint, the less time it takes to dry.
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