Manila copal

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Manila copal on glass (Visible light on left, UV light on right)

Description

A soft variety of Copal resin obtained from the Agathis dammara trees native to the Philippines and Indonesia. Manila copal is a diterpenoid resin composed primarily of polycommunic acid. Copals were used in the 18th and 19th centuries for varnishes and resin/oil media. Manila copals were also used in many Fixative recipes.

Synonyms and Related Terms

Agathis dammara; manilla copal (Br.); copal de Manila (Esp.); copale di Manila (It); Manila resin; manilla

Risks

  • Combustible, burning with a bright flame, dense smoke and strong smell.

Physical and Chemical Properties

  • Soluble in ether, methanol, and ethanol. Partially soluble in amyl alcohol. Insoluble in water.
  • Most copals fluoresce white in short-wave UV light.
  • Saponification number = 178
  • Acid number = 128.
  • Melting Point = 230-250 C
  • Density = 1.062 g/ml
  • Refractive Index = 1.544

Resources and Citations

  • K.van den Berg, J.van der Horst, J.Boon, "Recognition of Copals in Aged Resin/oil Paints and Varnishes" in ICOM Preprints, Lyon, 1999. p.855-861.
  • R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  • G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 227; synonym Boea copal
  • Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • "Copal: An Immature and Controversial Resin" at www.emporia.edu/earthsci/amber/copal.htm