Vermeer's Palette: Indigo

Indigo in Vermeer's Painting

Origin, History and Characteristics

Indigo was probably used as a painting pigment by ancient Greeks and Romans. Marco Polo (thirteenth century) was the first to report on the preparation of indigo in India. The indiagofera tinctoria plant thrives in a tropical climate; the active ingredient is found in the leaves. Aniline blue has the same chemical composition and replaced it in 1870. Indigo does not hold up well in an oil base but makes an excellent watercolor paint.

To prepare the dye, freshly cut plants are soaked until soft, packed into vats and left to ferment. It is then pressed into cakes for use as a watercolor or dried and ground into a fine powder for use as an oil paint. Bound with oil it is very transparent making it a good pigment for glazing. It has a strong yellow undertone. It has fair tinting strength and may fade rapidly when exposed to strong sunlight. Indigo has been used by artists and clothes manufacturing.

For many Dutch painters, "the pressing need for an extensive palette seems to have outweighed the risk that those colour harmonies would change over time. In their search for variety, these artists used not only costly pigments such as ultramarine, which was believed to age well, but also pigments that they knew were problematic. Indigo, for instance, fades when exposed to light. In the earlier seventeenth century, its poor reputation limited its use to underpaint, but by the middle of the century, painters, including high-life genre specialists, frequently used indigo in final paint layers."^{Adriaan Waiboer and Eddy Schavemaker, Vermeer and the Masters of Genre Painting: Inspiration and Rivalry (London and New Haven: Yale University Press, 2017), 69.}

English import duties in 1642 give an idea of the relative values of the blues available to painters of the time. "The merchandises listed do not include the ultramarine prepared as a pigment, but the duty for the raw material from which it was produced, lapis lazuli, was 10 shillings per pound. By comparison, the duty for indigo imported from the West Indies was 6s 8d, for smalt 1s 6d, and for verditer just 3d (Rates of Merchandizes 1642, pp. 18, 35, 53, 57). The extraordinary cost of prepared ultramarine is underscored by a table of Italian, French and English archival records comparing a wide range of prices of pigments; in the 1650s and 1660s ultramarine cost roughly forty times as much as smalt."^{Adriaan Waiboer and Eddy Schavemaker, Vermeer and the Masters of Genre Painting: Inspiration and Rivalry (London and New Haven: Yale University Press, 2017),280 n.11.}

During the first decades of the seventeenth century, the widespread use of indigo paint was likely a local Haarlem tradition initiated by Frans Hals. By the second half of the seventeenth century, painters from other cities in the Northern Netherlands began using indigo more frequently. The pigment is found in works by Vermeer, a still-life by Pieter de Ring of Leiden, and a portrait by Gerard van Honthorst, who worked in Utrecht, London, and The Hague after returning from Italy. Cornelis Johnson, primarily based in Utrecht, employed indigo in his Portrait of a Dutch gentleman. Indigo was consistently found in paintings by Jan Steen from the 1660s, particularly during his time in Haarlem from 1660 to 1670. Simultaneously, Peter Lely and, a few decades later, Godfried Schalken, both Netherlandish painters in England, also used indigo.

Few instances of indigo use are known in 18th and 19th-century oil paintings. This decline is likely due to the invention of Prussian blue in 1704, which became commercially available early in the 18th century. Prussian blue shared the positive qualities of indigo but was more fade-resistant.

Vermeer is known to have used indigo in only two works. It can be found in an admixture with smalt and in the deep blue robe (fig. 1) of the seated Christ in Christ in the House of Martha and Mary.The highlights on the drapery were intially painted with impasto, most likely a light blue, or pure lead white (smalt was also detected),and then glazed with pure indigo. The about 1-cm-wide brushstrokes suggest a square-tipped brush was used, likely made of hog's hair. This is the only deep blue color in Vermeer's oeuvre where natural ultramarine cannot be found.

The presence of indigo was recently detected with weld in a deep green glaze which covered the dark tone of the background of the Girl with a Pearl Earring. This glaze has almost entirely degraded. It was originally a smooth, glossy, translucent green that imparted depth and, perhaps, the precious quality of enamel to the background. Recent investigations suggest the background was not a flat, unmodulated layer of paint, but a dark green curtain.^{Vandivere, A., van Loon, A., Callewaert, T., et al. "Fading into the background: the dark space surrounding 'Vermeer’s Girl with a Pearl Earring.'" Herit Sci 7 (2019): 69.}