Walnut oil

Description

A natural, colorless drying oil pressed from the nuts of a walnut tree, Juglans regia. Walnuts contain approximately 65% oil. The cold-pressed oil is pale yellow while the hot-pressed oil has a green tinge. Walnut oil dries slower and yellows less than linseed oil, but it dries faster than poppy seed oil. It was popular as a paint medium in Italy, the Netherlands, and Germany. Walnut oil will turn rancid and develop a strong odor on storage.

Synonyms and Related Terms

nut oil; aceite de nueces (Esp.); huile de noix (Fr.); olio di noce (It)

Other Properties

Liquid is soluble in ethanol, ether, chloroform, turpentine, carbon disulfide. Saponification number = 188-197; Iodine number = 140-150 ; Acid value = 2.5

Density	0.919-0.927
Refractive Index	1.477-1.480

Hazards and Safety

Turns rancid and develops a strong odor on storage.

Authority

• Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)

• Reed Kay, The Painter's Guide To Studio Methods and Materials, Prentice-Hall, Inc., Englewood Cliffs, NJ, 1983

• Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000