Oil Pastel is a relatively new medium, considering that most  have been around for centuries.

In 1921, assisted and advised by artist and theorist Yamamoto, 2 brothers-in-law developed a high quality crayon, which combined the soft, smooth color application of crayon with the brightness of pastel. They continued to improve their product at the Sakura Crayon Company, and thus the name Cray-Pas was born. The final formulation was developed in 1927 and has been considered a children's medium, not one for the serious artist.
 

n 1947, artists Henri Goetz and Pablo Picasso approached Henri Sennelier with the idea of designing a professional version of the children's product. Picasso told Henri, "I want a colored pastel that I can paint on anything, wood, paper, canvas, metal, etc. without having to prepare or prime the canvas." Goetz wanted a pastel he could use to start oil paintings. He told Henri,  "If painting seems to be the complete of all pictorial techniques, then pastel is certainly the most direct. No instrument as the brush, knife or palette interferes between the artist's gesture and his work." Two years later in 1949, with the help of the two artists, Sennelier invented the first professional oil pastels. They had a creamy consistency with a brilliant color palette. The unusually wide range of grays were chosen specifically by Picasso. Later an assortment of iridescent and metallic pastels was added followed by fluorescents. Sennelier also makes a giant pastel, and more recently a new "Le Grande" size in the same color range as the standards.

Years later,  other brands jumped into the market - Caran d'Ache in 1981, Holbein in the early 80s with two grades of their oil pastels:  student and professional. Talens and Grumbacher added theirs at about the same time

Oil pastels use wax and inert oils as a binder making them non-yellowing and giving them excellent adhesion characteristics. They are completely acid free, and they never harden, thus they will never crack. Oil pastels can be applied to any paper, rigid support or fabric support without technical restraints, allowing the artist complete freedom of expression while maintaining archival stability.

History  References:

Sakura Web site : www.jellyroll.com
Oil Pastel by Kenneth Leslie
Glenn Brill, education director at Savoir Faire

FREQUENTLY ASKED QUESTIONS ABOUT OIL PASTELS (FAQs)

Q.    Do oil pastels need to be framed?

A.   Oil pastels will harden to some degree, but due to their wax and oil content they never     completely dry. Therefore they need to be framed behind glass for protection from the elements. Sometimes an acrylic varnish is applied over the pastels and this leaves a protective coat that does not need framing and can be gently wiped clean with a damp cloth.

Q.    Can oil pastels be mixed with other mediums?

A.  Yes they can be used with traditional oil painting mediums such as turpentine, mineral spirits and glazing mediums, and also acrylic mediums that have no water added.

Q.    What supports are good with oil pastels?

A.    Oil Pastels are a very versatile media. They may be used on any archival support such as paper, board, and canvas and even on metal and glass.

Q.    What are the differences between oil pastels, soft pastels, hard pastels, oil sticks and oil bars?

A.    All of these are made with the same pure pigments that are used in traditional oil paint. The difference is the binder and the fact that they are all formed into a stick or bar.

• Oil pastels are pure pigment in a fossil wax and mineral oil binder.

• Soft and hard pastels are the same; the difference is in their hardness only. Soft pastels are pure pigment with gum tragacanth as a binder.

• Oil sticks and oil bars are true oil paints, which are pure pigment and oil such as linseed, with a drying agent as a binder. They form a skin that can be peeled off for use.