The Search for the Perfect Color: Pigments, Tints, and Binders in the Scientific Expeditions to the Americas

Abstract

Interest in the natural world of the Americas began at the very moment when Europeans set foot on the continent. The natural abundance unfolding before their eyes held the promise of inexhaustible sources of capital, all of which would need to be documented. Francisco Hernández, Bernardino de Sahagún, José de Acosta, León Pinelo, and Bernabé Cobo are only a few of the names among an extensive number of chroniclers, explorers, and naturalists who dedicated themselves to investigate, categorize, and characterize the vegetable, animal, and mineral species of the New World between 1500 and 1700. Their written reports and artistically rendered illustrations of natural phenomena greatly broadened Spain’s appreciation of the potential wealth of the American colonies and motivated the Crown and its servants to invest more of its resources in the New World.Thanks in no small part to the Enlightenment, which viewed scientific progress as a tool for the improvement of society, agriculture, industry, and commerce, scientific interest in the natural world reached a notable momentum in the eighteenth century. This spirit of progress and the desire to optimize the use of natural resources led Europeans to promote scientific explorations in all of their overseas possessions, dramatically boosting botanical, zoological, geological, ethnological, and archaeological empirical studies.1The economic stagnation at the beginning of the eighteenth century persuaded the Bourbons to undertake a series of political reforms that would revive agriculture, industry, and commerce in Spain. This decision required greater knowledge about the geography and natural resources in the territories that formed Spain’s vast empire, fostering the generation of new economic sources. The Spanish monarchy supported several expeditions designed to improve the economy. The driving force behind them was King Charles III of Spain (1771–1792). With the information provided by these expeditions, the king intended to advance progress in science, commerce, industry, and agriculture, as well as to start natural-history collections under the auspices of the Royal Cabinet of Natural History and the Royal Botanical Garden, with help from Spain’s Royal Navy. The final authority for the expeditions—twenty of them during Charles III’s reign—rested with José de Gálvez, minister of the Royal and Supreme Council of the Indies, the most important government body overseeing the entire Spanish Empire, including the Americas, Asia, and Africa.The expedition teams were comprised of botanists, chemists, geologists, geographers, engineers, cartographers, and painters, who collected, classified, and methodically drew the different botanical, zoological, and mineral species; they also studied indigenous groups, folk customs, and archaeological monuments. They created herbarium, dissected animals, and collected live plants. All of this material was sent either to the Royal Botanical Garden or the Royal Cabinet of Natural History in Madrid. With the growing holdings of materials from the Americas and elsewhere, these two institutions could project an image of imperial power to the international world.There is no better example of the bounty produced for these imperial institutions than the “botanical expedition to the Viceroyalty of Peru” of 1777 to 1788—the first one organized during the reign of Charles III, dedicated to collecting and recording the natural history of both Peru and Chile, under the direction of Hipólito Ruiz, Joseph Dombey, and José Pavón. Even with disaster after disaster (shipwrecks, fires, etc.) resulting in the loss of invaluable material, the expedition managed to supply the Royal Botanical Garden of Madrid with more than 3,000 plant species and 2,500 botanical drawings. José Gabriel Rivera, Javier Cortés, José Rubio, Antonio Delgado, and Bruno Salvador Carmona returned to Madrid to create illuminations and engravings, resulting in the publication of Florae Peruvianae et Chilensis prodomus, published in three volumes (1794, 1798, and 1802), which disseminated these images to a wider audience.From 1783 to 1816, physician and naturalist José Celestino Mutis (1732–1808) led the botanical expedition to the New Kingdom of Granada, noted for its extraordinary level of botanical research. Thus began a remarkable forty-three-year scientific adventure, which, in addition to enlisting large teams of scientists, included sixty painters. Remarkably, the number of official painters sent from Spain proved to be insufficient. Mutis had to employ local painters living in the colonies, both Spaniards and Quiteños. In Santa Fe (Bogotá), Salvador Rizo, the expedition coordinator, created a school of drawing and painting for children that was to produce many botanical artists who helped to create Mutis’ Flora del Nuevo Reino de Granada (1783–1816).In time, the expedition teams began routinely to include both Europeans and locals. For example, the Royal Botanical Expedition to New Spain (1787–1803), led by the physician and botanist Martin Sessé y Lacaste, was joined by Mexican José Mariano Mociño, who had studied the fauna and flora of New Spain, the Antilles, Canada, California, and Central America. The expedition’s illustrations were created by two young colonial painters, Atanasio Echeverría and Godoy Juan de Dios Vicente de la Cerda.2The images created were expected to represent the shape and color of the original specimens faithfully as well as to convey scientific information in an objective manner (see Figures 1 and 2). The teaching of drawing was highly promoted in the eighteenth century; drawing was not only seen as an essential tool for art but also for learning and science. Consequently, drawing academies proliferated exponentially across Europe during this period. In Spain, they were created and supported by the “enlightened” institutions of the time, the Royal Societies (Reales Sociedades de Amigos del País). Academies taught life drawing with live models. Some of the academies had classes in flower painting, but, by and large, they tended to have an industrial focus, primarily of textile design.3The educated young artists who populated the natural-history expeditions had received no formal training in botanical drawing and illustration at their various academies. The majority of them viewed the expeditions as a way of further developing their botanical and naturalia skills. Löefling, a Swedish botanist and student of Carl Linnaeus, referred to Spanish artists Bruno Salvador Carmona and Juan de Dios Castel as “two young people who draw well, and on this occasion will study natural history, whereby they will acquire a more solid instruction to develop beginning at a young age.” Although both of them had studied at the Royal Academy of Fine Arts of San Fernando in Madrid and both were sons of artists—the famous sculptor Luis Salvador Carmona, also an instructor at the Academy, and silversmith Esteba Castel—they knew little about botanical drawing.4Atanasio Echeverría y Godoy and Juan de Dios Vicente de la Cerda, the colonial painters of the Royal Botanical Expedition of New Spain, were fresh from the Academy of Fine Arts of San Carlos in Mexico, recommended by its director. Joseph Brunete (Anton Meng’s pupil) and Isidro Gálvez, both academically trained, were selected to join the Viceroyalty of Peru expedition by Ignacio Hermosilla, the secretary of the Royal Academy of San Fernando. Unlike the vast majority of painters who enlisted in expeditions right after graduation, José Guío y Sánchez, a participant in the Alessandro Malaspina expedition, actually presented himself as a “painter of plants” (“pintor de plantas”), accomplished in the copying of nature, as well as an expert taxidermist. Mutis acknowledged in a letter to the viceroy, dated July 1778, that despite their academic backgrounds, the expedition draftsmen were working in an area that had no specialists in Spain: “Those chosen by the Royal Academy of San Fernando must show greater attention to the principles of art that academies teach their disciples; yet they lack as practicing artists in this painting genre that they have chosen and since the subject of Botany is new in Spain, they have lacked practice in this field.”5Mutis’ solution to this problem was to find local painters and train them as specialists; he had more confidence in their performance than in those who had gone through the academies. As he wrote to John of Villaluenga, president of Quito’s Royal Audience, in December 1787: “It has been and will continue to be easier to handle more docile although less skilled people, because I provide the foundational skills they will need to develop skill, and in this way, I compensate for the intractability of the Spanish officials, who are always proved wrong in America.” In another letter, he mentions two painters sent from the metropolis—José Calzado and Sebastián Martínez (a student of Mariano Maella)—both of whom trained at the Royal Academy of San Fernando in Madrid but had much to learn about a painting genre and technique with which they were unfamiliar: “I have to teach this genre of painting, and it costs me the same amount of work to train highly skilled officials or mere draftsmen.”6It was a different story with Pablo Antonio García de Campo, the first painter to join Mutis’ expedition, who had trained with the viceroy’s painter Joaquín Gutiérrez and had a reputation as a portraitist and religious painter. García began working with Mutis before the expedition and remained with him until he had to leave the expedition in 1784 for health reasons. The next two painters to join were also local but untrained—Francisco Javier Matís, who remained with the expedition from late 1783 until its dissolution in 1816, and Salvador Rizo, who enlisted as a cartographic draftsman in March of 1784. Rizo later supervised the technical direction of the iconography and the art school that Mutis founded, areas that complemented his other work as portrait painter, until his tragic death during the war for Colombian independence in 1812.The production of these early local artists, instructed in Mutis’ new school, was highly celebrated. Responsible for developing the first iconographies, they even earned the respect of Alexander von Humboldt (1769–1859), the father of botanical geography, who described them as the best painters of flowers in the world after seeing their work in the House of Botany (Casa de Bótanica) in 1801.7To alleviate his predicament, Mutis recruited a number of young painters with no academic training in Quito between 1786 and 1791. From autumn 1790 until June 1791, while headquartered in Santa Fe, he recruited draftsmen from Quito, Santa Fe, and Popayan, some of them from the schools run by Rizo in Mariquita and later in Santa Fe. For Mutis, absolute fidelity to visible reality was critical in the representation of natural history, not artistic creativity. Francisco Bruna, Dean (Oidor) of the Audiencia of Seville, who was in charge of selecting the artists for the Malaspina Expedition, noted in his report the need for artists able to “represent the living objects that not even the most skilled scribes could ever fully describe.”8Casimiro Gómez Ortega sought cartoonists with specialized skills for the Peruvian Expedition of 1777, which served as a model for other expeditions. Ortega also placed a premium on accuracy, although he allowed his artists to make additions from their “imagination” (“cosa alguna de su imaginación”). He also directed them to draw plants while they were still fresh, to utilize a uniform scale, and to use color for the major parts before they faded, filling in other colors later with India ink. Certain artists—Rizo, for one—drew outdoors under the direction of botanists/naturalists, noting shapes, textures, and colors.Plant specimens were typically gathered at sunrise, described as accurately as possible, and then moved to an office to be drawn. The plants were kept humid to prolong their preservation, original color, and the arrangement of leaves to facilitate accurate drawing. The entire process took two to three days: “[I]f too much time passes after being picked, the specimen starts to disfigure, and therefore does not represent or give a fair idea of its natural state.” Monochrome copies of completed drawings in sepia or black served as models for the recorder. Many of the drawings had no color, notwithstanding Ortega’s admonition. The short life span of plants, once picked, forced artists to work quickly and economically.9Artists employed watercolors for botanical drawing (see Figures 1, 2, and 3). Fast-drying and clean, this technique was well suited to fieldwork, sketches, visual notes, and cartography. Curiously, although watercolor technique became fashionable in Europe during the eighteenth century, Spanish-language art treatises or technical-instruction manuals barely mention it, with the exception of a brief reference in Antonio Palomino’s Pictorial Museum and Optical Scale (Madrid, 1715–1724). The first Spanish treatise that describes watercolor in detail (its nature, procedure, manufacture, binders, and pigments) is by the miniaturist Magadán—Experimental Notice to Practice Miniature Painting, Impastoed Painting, Illumination, Watercolors, and Pastel—a work aimed at dilettantes that did not widely circulate.10Mutis, however, left evidence that he was familiar with the treatises of Palomino and Magadán, among others. His interest in them must have stemmed partly from an attempt to increase his pupils’ skills. A mastery of oil painting did not translate into a mastery of watercolor painting. In a letter to Juan José de Villaluenga, Mutis outlined the skills that an expedition painter needed: “His skill at oil painting will serve as a suggestion for what should be learned about tempera paintings on paper. Provided that some are trained in the art of drawing and handling the brush they should be able to fill in the number [from a color chart; see below], especially if within the group, although beginners, they have recognized genius and apply themselves.” A month later, he made the same point to the president of the Royal Audience of Quito: “It was easier for me to acquire painters from the country, even with the work to teach these new styles of distemper painting, than to bring them from Spain with higher costs.”11His pupils’ inexperience with the technique of illumination, as well as managing their glue binders (agglutinates), probably prompted Mutis to ask Eloy Valenzuela, deputy director of the expedition, not to allow the artist Francisco Javier Matís to mix colors with glue but to use gum Arabic: “You can, in your mercy, ask for it in the pharmacy of San Juan de Dios in that city, or in Honda.” The Diario de Observaciones notes the following advice given from Pablo Caballero to Rizo: “Although this kind of distemper painting may be unfamiliar, [Pablo Caballero] has insinuated to his disciple Rizo that he should add Candia to the sugar gum. Rizo set off to experiment with the bath which he applied to the current sheet, and today it has been observed that leaves dry faster without that hardening glue that they have here. You might find this method better. Caballero says he has read it in author Palomino.”12Everyone was aware that if the expedition findings were to be disseminated, prints would have to be produced. Gómez Ortega’s instructions stipulated that all drawing paper be the same size as the printing plates in order to avoid modification in scale. Since Spain lacked printers or illuminators specialized in the areas of botanicals and naturalia, Casimiro Gómez Ortega created his own printing school to produce Peruvianæ Flora et Chilensis. In 1788, the Valencian painter José Rubio proposed to establish a school with six young printers, disciples of the Royal Academy of San Fernando, who would work under its jurisdiction, as well as a team of “chosen girls” from the Royal House of the Unfortunate (la Real Casa de los Desamparados de Madrid) to be in charge of coloring the sheets. This is by no means the only time that a female hand was known to have been involved in coloring prints. For example, the so-called “Geneva Ladies” (Damas de Ginebra) helped the Botanist Pyramus de Candolle in the hand coloring of Flora of Mexico.13Illustrations of scientific material required accurate colors and tones. Furthermore, a standardized nomenclature was necessary to ensure that visual information corresponded to the specimen. Unfortunately, the vagueness and subjectivity that surrounds color terms does not make such uniformity easy to attain. To avoid confusion resulting from different understandings of the same color, the English entomologist Moses Harris (c. 1788-1730) created a family of colors from the three primary ones identified by Isaac Newton. Harris published his color circle in The Natural System of Colours (London, 1766) and Exposition of English Insects (London, 1780). His interest was not so much in color theory as in devising a useful color chart to illustrate natural history.14But Harris’ was not the only color chart. Austrian naturalists and illustrators, Ferdinand Brauer (1760–1826) and his brother Franz (1758–1840) developed a color system in which each tone had a corresponding number. Since botanists in the field often had to work quickly, the use of the number system on the fly permitted them to apply color later, in the studio. The system that Ferdinand Bauer used on his expedition to the Mediterranean between 1786 and 1787 had at least 273 colors, with a tonal scale of 1 to 140 for each color; he added another 1,000 tones on his expedition to Australia (1801–1803). Bauer also had numerical codes for qualities like texture, which were helpful when illustrating animals, for example.15Among Thaddeus Haenke’s material archived at the Royal Botanical Garden in Madrid is a color chart that he brought on his trip to South America with the Malaspina expedition (see Figures 4 and 5). The study by Mabberley and San Pio described the chart as highly elaborate, containing 2,487 colors, numbered and annotated in Latin and German. In the center of the chart is a booklet of 273 colors written in a different hand, which, according to Lack and Ibáñez (1997), may have belonged to Bauer when he worked with English naturalist John Sibthorp in the Mediterranean (1786–1787). Haenke might have acquired the Bauers’ chart within the three years that he spent in Vienna as a member of Nikolaus Joseph von Jacquim’s (1727–1817) botanical circle, adding additional colors later.16Only a few examples of field drawings made during the Malaspina Expedition using this numbering system survive today. Mabberley and San Pio found a single sheet of the Royal Botanical Garden, Tradescantia zanonia (L.) Sw, partially colored by Haenke. The numbers on this drawing correspond to his chart, indicating the colors for the final drawing. Haenke’s color chart is the only one known to have actually been in use on an expedition.The Royal Botanical Garden supplied all of the materials and instruments necessary for the scientists and draftsmen on their expeditions, either in Madrid or in Cádiz, according to preserved lists compiled by the responsible parties. These lists show the quantities and qualities of the solicited and purchased materials: paper, brushes, resins and glues, pigments, lacquers, dyes, pencils, chemicals, books, and various instruments. The first such list is Löefling’s from 1754, which contains a variety of material colorants of mineral, vegetable, and animal origin, largely matching those mentioned by treatise writers (see Figure 6).Loefling’s palette contained eight basic colors: blacks—China ink, black, lampblack (“tinta de la china, negro, humo de pez”); blues—ultramarine, two types of Prussian blue, indigo, ashes from Santo Domingo (a mineral blue derived from copper?) (“azul ultramar, azul de Prusia en dos calidades, añil, cenizas de Santo Domingo”); violets—lichen (“horchilla,” or urchilla); reds—vermillion, three classes of carmine, red earth, red lead (“bermellón, tres clases de carmín, tierra roja, minio”); and yellows—gamboge-gum, yellow ochre (yellow lacquer/lake), orpiment, ochre, genulí (probably iron oxide), yellow glaze (probably lead antimoniate) (“gomagutta, ancorca [laca amarilla], oropimente, ocre, genulí [probablemente óxido de plomo], hornaza [probablemente antimoniato de plomo]”); greens—ordinary and distilled verdigris, green earth, bladder or sap green (probably of cochineal from Avignon) (“cardenillo ordinario y destilado, tierra verde, verde vejiga [probablemente de grana de Aviñón]”); whites—white lead (“albayalde”); and browns—Venetian coal and “old coal” (coal of unknown origin) (“sombra de Venecia y sombra ‘del viejo’ [sombra de origen desconocido]”).The materials also included gum Arabic, fish tail, white sugar, Jewish bitumen, brushes (of dog hair, squirrel, and mongoose), pencils (common, fine, blue lead, and black lapis), and other utensils (“goma arábiga, cola de pez, azúcar candí y bitumen judáico, así como pinceles [de perro, de ardilla, de meloncillo], lapiceros [comunes, finos, lapis plomo, lapis negro] y otros utensilios”).The expedition of Ruíz y Pavón to Peru and Chile took this list of items as a reference. The report of the articles delivered by the Madrilenian druggist, the court supplier, on September 20, 1777, has fewer pigments, however, than previous lists: fine lacquer of high quality (200 reals per ounce), fine ultramine and ashes of ultramarine, distilled green (verdigris), green earth, gamboge, toasted saffron, Jewish bitumen, vermillion, and fine ochre from Sienna. None of the reports specify great quantities of each pigment type, no more than a pound; it is unlikely that they were sufficient to cover the entirety of an expedition. In August 1789, the botanist Juan Tafalla and the painter Francisco Pulgar, expedition members in Peru, urgently pleaded from Lima for books, colors, and brushes. Their list included some new colorant substances, like saffron or “liquid blue” (azul líquido?), as well as more familiar ones (gamboge, vermillion, cochineal, lake/lacquer, and China ink). The materials arrived in October of the following year.The expedition painters were able to obtain the majority of the pigments and dyes recommended by the treatise writers in many of the great cities through which they passed—Bueno Aires, Lima, Quito, Cartagena, Mexico City, and others—where, since the sixteenth century, a fluid commerce with the metropolis had developed. Nonetheless, they apparently were not averse to doing their own experiments combining local and European vegetable and mineral substances, at least according to our information about Mutis’ lengthy stay in Santa Fe, to prepare their own dyes, pigments, and binders.Although they obtained many products commercially in Honda and Santa Fe, the extensive production generated by Mutis’ office and his school for Flora del Nuevo Reino de Granada probably required more and better colorant materials. Rizo seems to have prepared a report about his experiences with the preparation of colors, unfortunately lost—Practical Experiments for Miniatures, New Compositions of Colors for Miniatures, New Compositions of Colors for Imitation of the Vegetal Kingdom, Inventoried on the Royal Botanical Expedition of the New Kingdom of Granada for Its Flora. Mutis’ Daily Observations offers only a few facts about this activity. Among his correspondance and documentation about the expedition—preserved in the archive of the Royal Botanical Garden of Madrid (Real Jardín Botánico de Madrid)—are lists of purchases, expenditures, and sales (sometimes they sold products through third parties), some of them revealing the origin of their products: for example, “mermeyon” or vermillion; cochineal from Avignon (“granilla de Aviñón”); dragon’s blood, tumeric, or lake from the Orient (“laca de oriente”); Tragacanth gum (“goma alquitira”) or gum from Tragacanto; gum Arabic; linseed oil; Prussian blue; red lead (“azarcón”); verdigris (“cardenillo”); orpiment, as well as other chemical products (ammonia salt, rock alum, cream of tartar, vitriol oil [“aceite de vitriolo”], or sulfuric acid, distilled vinegar, Epson salt, nitric acid, and vitriol [another sulfate]).Other items on these lists were of American origin—such as logwood and cochineal—and thus under the monopoly of the Crown since the sixteenth century and tied to powerful overseas commerce. One of the red lakes, “carmín de grana” (from cochineal), an expensive material essential for the rosy variations of flowers, was especially in demand; painters normally procured it directly from the boats docking in Cartegena from Europe or New Spain.Green tones were a constant preoccupation. The documents of the expedition carry scattered notes about experiments to obtain green dyes with vegetable extracts, some from a plant identified as “el molo,” possibly Miconia spp., from the Glory-bush family: “Concentrate ‘el molo’ … was kept in a full lunette. In effect all this quantity has thickened and been reduced to the quantity of a catch basin. The yellow is pretty, but mixed with Prussian blue it becomes a disagreeable green. Mixed with vitriol blue (copper sulfate blue vitriolic) from La Grita, and the green is pretty, but it resists a bit being worked. The ground is made from the bean tree and the dye doesn’t offer hope of any color. I mixed a little copper sulfate in a tincture of it and the color became yellowish in a disagreeable greenish-black.”17Other green dyes came from a mixture of lakes and pigments—for example, gamboge with blue from La Grita, “from which can result two greens” (“de la que pueden salir dos verdes”); or Prussian blue with orpiment. In a notation from the Daily Observations, Mutis signaled the use of “watercolor green for washes” (“verde de las aguadas para los planos”): “In little time, it became standard to paint a sheet where the green is separated from the watercolors for the washes and for all the background, with the green that results from the mixture of gamboge with the blue from La Grita. Said drawing was very beautiful and full of grace, and it seems to us that we can follow with the rest.”18We do not know the specific pigment meant by the phrase “verde de las aguadas para los planos,” though it was probably a verdigris (copper acetate), an artificial pigment of green-blue color frequently used to represent water in backgrounds; in fact, it was known as “water color” (“color de agua”). Eighteenth-century treatises mention other greens obtained from vegetable extracts that were used for washes on maps: bladder green, or “sap green” (“el verde vejiga”), from cochineal in a berry belonging to a bush of the genus Rahmnus in Avignon, green iris obtained from lily petals, or the mixture of a blue (indigo or verdigris) with a yellow (gamboge). The workshops of La Flora in New Granada also kept these mixtures, except for green iris, which was probably replaced with extracts from local vegetable species.19Blue from La Grita, a pigment of mineral origin (copper carbonate or silicate?) obtained in copper deposits after 1625 in La Grita, Venezuela, received mention on occasion. Simón, in his Noticias Historiales o conquista de Tierra Firme en las Indias occidentales (1629) called painters’ attention to the existence of a mine of fine blue stone (“powders of blue ground”) close to La Grita. The news began to spread during the eighteenth century, thanks to a publication by Juliá about the Venezuelan region. Juliá reported the popularity of this blue stone among local painters, cautioning that although it was obtainable in Santa Marta and Santa Fe at four scuds per pound, its only real commercial availability was in Quito: “It is a beautiful blue, clear and celestial to the eye; many painters appreciate and often ask for it and mix it, according to the regulations of art, with Prussian blue, making a warm blue, not too light, not too dark.” Consistent with Juliá’s warning, there is no evidence of anything more than small-scale commerce in this material. It might not have been able to compete with the market for Prussian blue, the artificial pigment that prevailed in Europe from the mid-eighteenth century onward because of its chemical properties and good optics.20The representation of natural specimens had to be accurate for the sake of scientific objectivity. The technique of watercolor (illumination and miniature—“watercolor,” according to the terminology of the period) proved apt for scientific illustration and industrial design due to its chromatic qualities, its neatness, and its ease of use in the field, thus accounting for its development during the eighteenth century. The color charts that increasingly served as guides for scientific, cartographical, and industrial illustration during this century were employed to great effect by draftsmen and print illuminators to represent botanicals. Haenke relied on one, probably based on that of the Bauers’, for some of his fieldwork during the Malaspina expedition.The scientific expeditions organized by the Spanish Crown devoted special attention to the study of nature, though few of the artists who participated in them entered as specialists in the genre, notwithstanding their academic backgrounds. The fact that only Magadán’s treatise of 1754 and Martínez’s Dictionary of 1788 provide detailed information about the procedures of, and suitable materials for, miniature and illumination, indicates their low profile during the second half of the eighteenth century. Conscious of this lacuna, Mutis created a school of botanical draftsmen for his Flora del Nuevo Reino de Granada.Control of suitable pigments was the other indispensable requirement for scientific objectivity. The Spanish documentary evidence indicates the colorant materials of choice. The Minster of the Indies provided funding for the pigments, lacquers, adhesives, resins, brushes, papers, pencils, and chemical products requisitioned by the expeditions, and he arranged for supplies to be sent later. The lists of materials show that quantities shipped were not large, probably meaning that supplies had to be obtained, whenever possible, in the cities along the way—Buenos Aires, Lima, Quito, Santa Fe, Mexico City, etc.—where sometimes the same materials were available as in Europe.Only the expedition to the Nuevo Reino de Granada, however, details the supply in the local market (Honda, Santa Fe, or Cartagena). The length of this expedition and the creation of a school of draftsmen to sustain it fostered an interest in local substances to improve the repertoire of colors and achieve optimal chromatic quality, the success of which is reflected in the beautiful scientific and artistic production of the Flora.Continued research into the Spanish Crown’s scientific expeditions to the Americas provides important information not only about the history of science but also about the history of art. Primary sources reveal the names of the Spanish artists who accompanied these expeditions, as well as the ways in which they adapted to the new genre of botanical illustration, and they promise to shed new light on the education of artists in the Americas during the eighteenth century—a topic understood poorly until recently. Color charts and requisitions provide new information about the materials used for botanical drawings, the attempt to standardize color, and the development of watercolor. Artists frequently employed materials of European origin, but the sources that document the acquisition of indigenous Latin American materials offer instructive new data.Art historians still have much to learn about the training of, and the interactions between, artists from Spain and the Americas. Interdisciplinary collaborations between conservation scientists and art historians is an especially valuable next step. Subjecting more drawings to tests could reveal their exact colorants and materials and thus prove or disprove the accuracy of the documentary evidence. Furthermore, technical examination of the drawings produced across the Americas by the various expeditions could help scholars to map the use of materials. Did different locations tend to rely on different materials? How popular were local pigments? Conceivably, our knowledge about origins and composition could become deep enough to permit early American artwork to infiltrate the canon of primary sources, or even to serve a forensic function. At this juncture, a world of possibility lies ahead.