Difference between revisions of "Asphaltum"

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1) An old name for [[asphalt|asphalt]] generally used prior to the 1800s.  
 
1) An old name for [[asphalt|asphalt]] generally used prior to the 1800s.  
  
2) In the 17th and 18th centuries, the term asphaltum also referred to a transparent brown, [[asphalt|asphalt]]-based pigment used in [[watercolor%20paint|watercolor]] and [[oil%20paint|oil paints] for glazes and shadows. The oily material can slow the drying of [[linseed%20oil|linseed oil]] producing a soft film. With time, asphaltum in dried oil films can result in the movement or disfigurement of the film as well as [[allligator%20crack|allligator cracks]]. Asphaltum was sold commercially as a transparent brown artist pigment under the name bitumen (Gettens and Stout 1966).
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2) In the 17th and 18th centuries, the term asphaltum also referred to a transparent brown, [[asphalt|asphalt]]-based pigment used in [[watercolor%20paint|watercolor]] and [[oil%20paint|oil paints] for glazes and shadows. The oily material can slow the drying of [[linseed%20oil|linseed oil]] producing a soft film. With time, asphaltum in dried oil films can result in the movement or disfigurement of the film as well as [[alligator%20crack|alligator cracks]]. Asphaltum was sold commercially as a transparent brown artist pigment under the name bitumen (Gettens and Stout 1966).
  
 
== Synonyms and Related Terms ==
 
== Synonyms and Related Terms ==
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[[[SliderGallery rightalign|Asphaltum, Forbes Raw Materials.TIF~FTIR]]]
 
[[[SliderGallery rightalign|Asphaltum, Forbes Raw Materials.TIF~FTIR]]]
  
== Other Properties ==
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== Risks ==
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Combustible. Softens at slightly elevated temperatures. 
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Ages poorly in dried oil films resulting in movement, disfigurement and/or cracks.
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== Physical and Chemical Properties ==
  
 
Soluble in petroleum hydrocarbons, turpentine, and most organic solvents.  Partially soluble in oils.
 
Soluble in petroleum hydrocarbons, turpentine, and most organic solvents.  Partially soluble in oils.
  
 
Microscopic ID: amorphous, brown particles with conchoidal fracture and/or curved particle boundaries. RI < 1.662. Isotropic in crossed polars.  
 
Microscopic ID: amorphous, brown particles with conchoidal fracture and/or curved particle boundaries. RI < 1.662. Isotropic in crossed polars.  
 
== Hazards and Safety ==
 
 
Combustible. Softens at slightly elevated temperatures. 
 
 
Ages poorly in dried oil films resulting in movement, disfigurement and/or cracks.
 
  
 
== Additional Images ==
 
== Additional Images ==
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== Additional Information ==
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== Resources and Citations ==
 
 
° R.White "Brown and Black Organic Glazes, Pigments and Paints" ''National Gallery Technical Bulletin'', 10:58-71, 1986. ° R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
 
  
== Sources Checked for Data in Record ==
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* R.White "Brown and Black Organic Glazes, Pigments and Paints" ''National Gallery Technical Bulletin'', 10:58-71, 1986. ° R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  
 
* R. J. Gettens, G.L. Stout, ''Painting Materials, A Short Encyclopaedia'', Dover Publications, New York, 1966
 
* R. J. Gettens, G.L. Stout, ''Painting Materials, A Short Encyclopaedia'', Dover Publications, New York, 1966

Revision as of 14:00, 11 August 2020

1993.775-SC31053.jpg

Description

1) An old name for Asphalt generally used prior to the 1800s.

2) In the 17th and 18th centuries, the term asphaltum also referred to a transparent brown, Asphalt-based pigment used in watercolor and [[oil paint|oil paints] for glazes and shadows. The oily material can slow the drying of Linseed oil producing a soft film. With time, asphaltum in dried oil films can result in the movement or disfigurement of the film as well as alligator cracks. Asphaltum was sold commercially as a transparent brown artist pigment under the name bitumen (Gettens and Stout 1966).

Synonyms and Related Terms

2) bitumen; Antwerp brown; asphalt paint; Asphalt (Deut.); asfalto (Port.); asphalte (Fr.); asfalto (Esp.); asfaltos (Gr.); alfalto (It.); bitume (It.); asfalt (Ned.); asfalto (Port.)

FTIR

Asphaltum, Forbes Raw Materials.TIF


Risks

Combustible. Softens at slightly elevated temperatures.

Ages poorly in dried oil films resulting in movement, disfigurement and/or cracks.

Physical and Chemical Properties

Soluble in petroleum hydrocarbons, turpentine, and most organic solvents. Partially soluble in oils.

Microscopic ID: amorphous, brown particles with conchoidal fracture and/or curved particle boundaries. RI < 1.662. Isotropic in crossed polars.

Additional Images


Resources and Citations

  • R.White "Brown and Black Organic Glazes, Pigments and Paints" National Gallery Technical Bulletin, 10:58-71, 1986. ° R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
  • 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)
  • Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
  • R.D. Harley, Artists' Pigments c. 1600-1835, Butterworth Scientific, London, 1982
  • Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
  • Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
  • Eastaugh, N. et al. The Pigment Compendium, a Dictionary and Optical Microscopy of Historical Pigments, Butterworth-Heinemann, 2008.

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