Gamboge

Gamboge is a deep-yellow pigment derived from a species of tree that primarily grows in Cambodia. Popular in east Asian watercolor works, it has been used across a number of media dating back to the 8th century. Easy to transport and manipulate into a durable watercolor paint, gamboge is notable for its versatility as a pigment in how it has been used in paintings, printing of books, and garment dyes, including the robes of Buddhist monks. Though used in a number of different contexts, Gamboge is known not to react well with citric acid surfaces therefore making it unsuitable for frescos and with white lead. For its popularity, Gamboge has not been extensively identified in works of art from any time period; the few instances wherein art historians have attempted to identify whether or not the pigment was used in a given work have confirmed its widespread use and its longevity as staple within watercolor painting particularly in eastern art.

History
Gamboge’s first recorded use dates back to the 8th century during which time it appeared in Japanese art. Some historians speculate small shipments of the pigment were able to be distributed in European contexts due to the occasional over-land trade journeys made from Asia to Europe. Gamboge would become much more accessible beginning in the 17th century as shipping grew in popularity as a method of transporting goods from Asia to Europe. It was around this time that Gamboge’s popularity in watercolors grew tremendously.

The pigment is derived from the gum of a species of evergreen of the family Guttiferae which grows in southeast Asia, primarily Cambodia and Thailand. In fact, Gamboge gets its name from a now-antiquated name for Cambodia, Camboja, though it was also referred to as gama gitta in some 17th century European color manuals. The pigment is extracted from Guttiferae trees through a process of cutting several deep incisions into the tree’s trunk thus allowing the resin to bleed out into pre-mounted bamboo canes used as receptacle to initially catch and later transport the product. The practice of collecting Gamboge in bamboo cane was so widespread and recognizable that the pigment was often referred to as “pipe Gamboge” for how it conformed to the cylindrical shape of the receptacle.

There was a brief shortage of the pigment during the 1970s and 1980s due to trade restrictions placed on the Khmer Rouge regime. It was during this time that shipments of the gum which makes Gamboge were found to contain bullet casings and other impurities which tainted the pigment.

While Gamboge is best known for its use in artwork, it does have a secondary function as a laxative. In small doses it can cause watery feces while large doses have been reported to cause death.

Production
Gamboge is most often extracted by tapping latex (sometimes incorrectly referred to as sap) from various species of evergreen trees of the family Clusiaceae (also known as Guttiferae). The tree most commonly used is the gamboge tree (genus Garcinia), including G. hanburyi (Cambodia and Thailand), G. morella (India and Sri Lanka), and G. elliptica and G. heterandra (Myanmar). The orange fruit of Garcinia gummi-gutta (formerly called G. cambogia) is also known as gamboge or gambooge.

The trees must be at least ten years old before they are tapped. The resin is extracted by making spiral incisions in the bark, and by breaking off leaves and shoots and letting the milky yellow resinous gum drip out. The resulting latex is collected in hollow bamboo canes. After the resin is congealed, the bamboo is broken away and large rods of raw gamboge remain.

Visual characteristics
Once extracted from the trees in which it is found, Gamboge resin has a brownish-yellow color. Once ground, the resin takes on a deep yellow color. Artists sometimes combined Prussian blue with gamboge to create green; they also mixed it with burnt sienna to make orange.

Gamboge was most commonly used in watercolor painting.

Permanence
Gamboge is highly sensitive to light. It is known to react poorly with lime surfaces and, as such, is deemed unsuitable for frescos. Gamboge is also known to react with white lead.

Notable occurrences
Gamboge has not been extensively identified in works of art from any time period; many analyses of paintings simply identify the presence of "organic yellow" without distinguishing between different organic yellow pigments.

Gamboge has been identified as the underlying gold paint in the Maitepnimit Temple in Thailand as well as having featured in the Medieval Armenian Glajor Gospel. Though not authenticated, it has also been noted that Rembrandt may have used the pigment in a few of his works and that it appears in J. M. W. Turner's color box.

Etymology
The word comes from gambogium, the Latin word for the pigment, which derives from Gambogia, the Latin word for Cambodia. Its first recorded use as a colour name in English was in 1634.