These were superior in wax viscosity, texture and pigment quality and
capable of producing more consistent and attractive work. The Japanese
Holbein brand of oil pastel appeared in the mid-1980s with both student
and professional grades; the latter with a range of 225 colours. Another
brand, Caran d'Ache, introduced Neocolor wax crayons onto the market in
1965, using a patented polyethylene wax with superior lubrication; in
the nineties these were developed into an oil pastel, Neopastle.
Using Oil Pastels
Oil pastels can be used directly in dry form; when done lightly, the
resulting effects are similar to pastel chalks. Heavy build-ups can
create an almost impasto effect. Once applied to a surface, the oil
pastel pigment can be manipulated with a brush moistened in white
spirit, turpentine, linseed oil, or another type of vegetable oil or
solvent. Alternatively, the drawing surface can be oiled before drawing
or the pastel itself can be dipped in oil. It should be noted that all
these solvents pose serious health concerns.
Since oil pastels are a relatively new invention, the effects of dust
and light on oil pastel works is not yet known; inability to age
gracefully would limit their value in galleries, so many are translated
into a print form by lithography or its variant glicées. Oil pastels are
considered a fast medium because they are easy to paint with and
convenient to carry; for this reason they are often used for sketching,
but can also be used for sustained works.
Because oil pastels never dry out completely, they need to be protected
somehow, often by applying a special fixative to the painting or placing
the painting in a sleeve and then inside a frame.
There are some known durability problems: firstly, as the oil doesn't
dry it keeps permeating the paper. This process degrades both the paper
and the colour layer as it reduces the flexibility of the latter. A
second problem is that the stearic acid makes the paper brittle.
Lastly both the stearic acid and the wax will be prone to efflorescence
or "wax bloom", the building-up of fatty acids and wax on the surface
into an opaque white layer. This is easily made transparent again by
gentle polishing with a woolen cloth; but the three effects together
result in a colour layer consisting mainly of brittle stearic acid on
top of brittle paper, a combination that will crumble easily.
A long term concern is simple evaporation: palmitic acid is often
present and half of it will have evaporated within forty years; within
140 years half of the stearic acid will have disappeared. Impregnation
of the entire art work by beeswax has been evaluated as a conservation
Surface and techniques
An example of the scraping down technique. The surface chosen for oil
pastels can have a very dramatic effect the final painting. Paper is a
common surface but this medium can be used on other surfaces including
wood, metal, masonite, canvas and glass. Many companies make papers
specifically for pastels that are suitable for use with oil pastels.
Building up layers of color with the oil pastel, called layering, is a
very common technique. Other techniques include underpainting and
scraping down or sgrafito. Turpentine, or similar liquids such as
mineral spirits, is often used as a blending tool to create a wash
effect similar to some watercolor paintings.
from Wikipedia, The Free Encyclopedia