Pigmentos Naturales

Guión para el vídeo: https://youtu.be/eH_rcAKLMyo.
En prácticamente todos los manuscritos medievales encontramos además tintas de al menos un color más, aunque solo sea para los títulos. Y en este vídeo vamos a ocuparnos precisamente de esas tintas de colores. Veremos de qué fuentes disponemos para conocerlas, qué componentes se empleaban para conseguir los distintos colores, y cómo se fabricaba la pintura o tinta.

"The megalithic tomb at Montelirio is off the scale in more ways than one. As well as being the largest example of its type known in Spain, the burial goods secreted in its subterranean chambers are unsurpassed in both quantity and quality. Leonardo García Sanjuán reveals what the dead of Montelirio can tell us about Copper Age society."

The social man creates or borrows practical procedures, and with them specific phrases. Unfortunately present literature often separates these phrases from the techniques in which the same phrases are used. This is the case of the colour term 'azure' and 'lapis lazuli' that denotes today an aggregate of minerals from which the pigment ultramarine 'blue' was extracted in the course of the Middle Ages. The present work collects well-established pieces of information from a multidisciplinary standpoint with the aim of highlighting the various social utilisations of ground lapis lazuli, or better, its 'blue' mineral called lazurite. New data is extracted from the Thesaurus Linguae Graecae, and Medieval Latin manuscripts (MSS) devoted to colour making. The oldest Western use of the pigment ultramarine 'blue' preceded of about seven centuries the first three 13th-14th century recipes, which describe the production of the pigment from lapis lazuli. This enormous time gap requires a new interpretation of the social mechanisms that transmit practical arts. Available chemical data refutes the hypothesis of a single mining supply source for archaeological findings of lapis lazuli, and new evidence demonstrates also that the phrase ultramarine 'blue' is strongly misleading. The term 'blue' became a basic colour term most likely in the early 15 th century England. Instead, the Medieval Latin word 'lazurum' and the corresponding Vernacular terms drew from lazurin, a 9 th century A.D. transliteration of the Greek λαζούρ (lazour), attested since the 4 th century A.D. The latter stemmed from the Persian colour term lājvard, which denoted lapis lazuli and other 'blue' substances. This study paves the way for the study of the intricate social utilisations of an 'azure' pigment that was successively called ultramarine 'blue', and on the first linguistic evidence of the term 'azure'.

El fin de este trabajo es documentar algunos de los pigmentos más utilizados en la paleta cromática de Jan Van Eyck, se eligió a este artista debido a que la mayoría de sus obras se encuentran en buen estado de conservación, además de ser uno de los primeros artistas en emplear y dominar el óleo.

This paper aims to offer a a broad view of trade
in painters’ materials in the Spanish peninsula
in the sixteenth century, from their production
to their import and export. Factors such as their
being documented in archival sources or their
availability are also considered in establishing
their multiple relationships in the contextual
framework of growing globalization. Although
they constituted uncategorized products in a
very heterogeneous market, they have been
grouped in pigments and colorants. Generally,
their main uses had nothing to do with painting;
some of them were would have fallen under
the definition of dyes, others were used as
medicines, and yet others were basic products
for the glass and ceramic industries. This paper
explores the presence and role of many of those
substances in the development of Renaissance
painting

Background: Color change in artworks has been commented on for centuries. Fading of watercolor pigments is a notable alteration. Pigments based on carminic acid are among those particularly prone to color loss, but the mechanism and factors are not well understood. Results: We painted out three pigments prepared from the aqueous extract of carminic acid (CA) from Dactylopius coccus: the uncomplexed, and aluminium-and tin-complexed lakes. These were applied in a 2% gum Arabic solution to papers that were acidic, neutral or alkaline pH and exposed to accelerated light aging in a weatherometer. The comparative rate of fading was dependent on the complexation and on the pH of the substrate. On alkaline paper, the Al complex was least light stable, on neutral paper the three colorants responded similarly, and on acidic paper the tin complex was the least light stable. This is discussed in light of the published information on reactions and mechanism of color loss of CA.

The social man creates or borrows practical procedures, and with them specific phrases. Unfortunately present literature often separates these phrases from the techniques in which the same phrases are used. This is the case of the colour term ‘azure’ and ‘lapis lazuli’ that denotes today an aggregate of minerals from which the pigment ultramarine ‘blue’ was extracted in the course of the Middle Ages. The present work collects well-established pieces of information from a multidisciplinary standpoint with the aim of highlighting the various social utilisations of ground lapis lazuli, or better, its ‘blue’ mineral called lazurite. New data is extracted from the Thesaurus Linguae Graecae, and Medieval Latin manuscripts (MSS) devoted to colour making. The oldest Western use of the pigment ultramarine ‘blue’ preceded of about seven centuries the first three 13th-14th century recipes, which describe the production of the pigment from lapis lazuli. This enormous time gap requires a new int...

CAROTENOIDES Constituyen un grupo de pigmentos amarillos, rojos y naranjas, distribuidos en casi todos los organismos vivos. Generalmente los carotenoides son insolubles en agua pero se disuelven fácilmente en grasas y en alcohol. Dan el color naranja a las naranjas, mandarinas, zanahorias, duraznos, el rojo amarillento de los jitomates, y algunos mariscos, así como el amarillo de la yema de huevo, el maíz y la piel de pollo, etc. En los mariscos los carotenoides se encuentran unidos a una proteína. Para obtener la vitamina B (liposoluble: se disuelve solo en grasa/alcohol) de la zanahoria es necesario prepararla en grasa ya que en jugo, cruda o en caldo solo obtendrás los azúcares. Como habrá sospechado el antojadizo lector este complejo caroteno-proteína se rompe con la temperatura (generalmente los mariscos pasan por agua hirviente antes de llegar a la boca de comensal), lo que da lugar al color rojo naranja de los carotenoides en los camarones. El mismo resultado se obtiene con alcohol.

Austin: University of Texas Press, 2017.
Using extensive and largely unpublished archival documentation, this major new work recovers the first century of artistic practice in colonial Quito, one of colonial South America's most important artistic centers.

Procesos: revista ecuatoriana de historia 43 (2016): 37-64.
Basado principalmente en documentación inédita, este estudio cubre una gama de materiales, así como modelos artísticos, disponibles para pintores en el mercado local desde comienzos de la colonia. Incluye tanto grabados como pinturas importadas, sus temas, características y precios; los pinceles, soportes, pigmentos, aglutinantes, secantes y otros elementos de confección pictórica; así como las condiciones del mercado en la compraventa de materiales y obras de arte. La evidencia muestra la riqueza de modelos y materiales, tanto locales como importados, que tuvieron a su alcance los primeros pintores quiteños.

Background: Color change in artworks has been commented on for centuries. Fading of watercolor pigments is a notable alteration. Pigments based on carminic acid are among those particularly prone to color loss, but the mechanism and factors are not well understood. Results: We painted out three pigments prepared from the aqueous extract of carminic acid (CA) from Dactylopius coccus: the uncomplexed, and aluminium-and tin-complexed lakes. These were applied in a 2% gum Arabic solution to papers that were acidic, neutral or alkaline pH and exposed to accelerated light aging in a weatherometer. The comparative rate of fading was dependent on the complexation and on the pH of the substrate. On alkaline paper, the Al complex was least light stable, on neutral paper the three colorants responded similarly, and on acidic paper the tin complex was the least light stable. This is discussed in light of the published information on reactions and mechanism of color loss of CA.

The social man creates or borrows practical procedures, and with them specific phrases. Unfortunately present literature often separates these phrases from the techniques in which the same phrases are used. This is the case of the colour term ‘azure’ and ‘lapis lazuli’ that denotes today an aggregate of minerals from which the pigment ultramarine ‘blue’ was extracted in the course of the Middle Ages. The present work collects well-established pieces of information from a multidisciplinary standpoint with the aim of highlighting the various social utilisations of ground lapis lazuli, or better, its ‘blue’ mineral called lazurite. New data is extracted from the Thesaurus Linguae Graecae, and Medieval Latin manuscripts (MSS) devoted to colour making. The oldest Western use of the pigment ultramarine ‘blue’ preceded of about seven centuries the first three 13th-14th century recipes, which describe the production of the pigment from lapis lazuli. This enormous time gap requires a new int...

Background: Color change in artworks has been commented on for centuries. Fading of watercolor pigments is a notable alteration. Pigments based on carminic acid are among those particularly prone to color loss, but the mechanism and factors are not well understood. Results: We painted out three pigments prepared from the aqueous extract of carminic acid (CA) from Dactylopius coccus: the uncomplexed, and aluminium-and tin-complexed lakes. These were applied in a 2% gum Arabic solution to papers that were acidic, neutral or alkaline pH and exposed to accelerated light aging in a weatherometer. The comparative rate of fading was dependent on the complexation and on the pH of the substrate. On alkaline paper, the Al complex was least light stable, on neutral paper the three colorants responded similarly, and on acidic paper the tin complex was the least light stable. This is discussed in light of the published information on reactions and mechanism of color loss of CA.

Medieval plasterwork currently faces preservation issues due to the lack of cohesion between their polychrome sections, which, if not adequately treated in time, cause the irretrievable loss of their original appearance. It is relatively frequent to observe how the plasterwork preserve only scarce remains of their original color appearance in monuments like the Alhambra, the Alcazar in Seville or in pieces stored in Archeological Museums all over the world. The loss of vividness in the color of the plasterwork has been caused mostly by exposure to humidity, aggressive cleaning agents or by superposed paint layers applied at a later period. In view of these facts, the main aim of this study is to determine the best consolidant of choice to fix and preserve medieval plasterwork, from a colorimetric perspective. A set of 48 plaster probes have been built and the polychromy has been applied according to the procedures and materials used in the mediaeval period. Each probe was 6.5 x 13 cm in size, and three different natural pigments have been applied on 16 probes each (natural azurite, cinnabar and lead red) with two different binders (animal glue and arabic gum). Figure 1 shows an instance of one of the probe series for lead red. In the study, the methodology used to evaluate the color changes induced by six different consolidants is presented, and the results analyzed. The consolidants are: ethyl silicate (Estel 1200, BE), ethyl silicate (Nanoestel, NE), acrylic resin (Paraloid® B72, PAB72), hydroxypropyl cellulose (Klucel®G, KL), polyvinyl butyral (Mowital® B60H, MW) and thermoplastic polymer (Aquazol®, AQ). Two factors have been analyzed in the preliminary results: uniformity of the applied pigments across probes, and effect of applying the consolidant on the probes, in average across the different pigments. For the first time to our knowledge, a hyperspectral imaging system (Resonon PikaL camera) has been used to measure the spectral reflectance of the probes before and after applying the consolidants. Using the spectral reflectance data, CIEDE00 color difference and two additional spectral difference metrics (Root-Mean-Square-Error or RMSE and Goodness-of-Fit coefficient or GFC) have been computed between corresponding probes to analyze the two factors mentioned above. Besides, changes in perceptual attributes like Lightness, Chroma and Hue have been studied using the CIELAB color coordinates of the samples. Figure 1. Left: Lead Red probes prepared for spectral reflectance measurement with the PikaL system (center). Right: CIEDE00 results comparing the probes before and after the consolidants have been applied, in average for the three pigments used. The results show that the least homogeneous pigment across probes is azurite, due to the effect of the grind size on the pigment obtained and the difficulty of the binding process. Also, the least homogeneous binder is arabic gum. Regarding the effect of applying the consolidant, the Klucel® is the agent that best preserves sample color, and Mowital®B60H is the consolidant which causes the most noticeable change in color in average across pigments. The use of a hyperspectral capture device will enable us to analyze the effect of the consolidant agent in the local spatial texture of the sample, which poses an additional advantage over traditional area-based color measurement devices. This methodology is also potentially valid to perform colorimetric quality assessments of other preservation actions for plasterworks, like cleaning and color reintegration operations.