Today, I was fortunate enough not only to visit the Arthur M. Sackler Museum at Harvard University, but also to hear three of the museum’s conservation staff discuss their work with the exhibition In Harmony: The Norma Jean Calderwood Collection of Islamic Art. Only donated to the museum in 2002, the Calderwood Collection includes a wide variety of ceramic wares from across the Islamic world in the mediaeval period, as well as a stunning array of manuscript illuminations in the Persian tradition.
The discussion, entitled From the Laboratory to the Gallery: The Conservation and Technical Study of Islamic Art, began by delving into these paintings, most of which illustrated scenes from Firdowsi’s Shahname, or ‘Book of Kings’. Written in the 10th century, the Shahname relates the mythic and historical past of Iran and became, over the course of the following centuries, an icon of Persianate culture. Elaborate decorated manuscripts of the text were symbols of wealth and taste to the rulers of the later Middle Ages; vividly coloured and exquisitely detailed, they display the fantastic accomplishments of royal artisans.
Their abilities, however, went far beyond the aesthetic. Unlike most European manuscripts, these were created not on vellum, but on paper burnished smooth. Many different artists, including calligraphers as well as painters, would collaborate to create these scenes. Although many such works were dispersed for sale on the art market, analysis of the techniques and pigments–which used minerals like lapis lazuli and hematite–has allowed many works from the same volumes to be displayed together.
Then the talk moved to the collection’s ceramics, and the potter’s quest for ever more perfect colours and effects. Most Islamic ceramic ware, whether Egyptian, Iranian, or Iraqi, strove to manipulate the chemistry of glazes in pursuit of a single goal–a brilliant white surface on which to render elegant surface decorations. Early attempts required a white slip (outer layer) laid over darker earthenware vessels, but later Islamic artisans developed the new form of stonepaste, or fritware. Relying on complex chemical knowledge and a mastery of the firing process, fritware created a creamy white ceramic base without the added layer.
Additional effects, from brilliant yellow glazes to shining lustrous coppers, also depended on a virtuosic knowledge of minerals and their interactive properties. In fact, even with modern scientific analysis, scholars still do not know precisely how some colours were achieved. Using ultraviolet light, x-ray machines–and even CT scanners–however, they can gauge the integrity of pieces without tedious (and potentially damaging) disassembly.
These technical investigations are illuminating not only the physical properties of these artworks, but also highlight the extraordinary skill of those who made them. Whether working in ceramic or on paper, Islamic artisans manipulated natural materials to stunning effect. Combining chemistry with their already excellent understanding of harmony, proportion, and colour, they created enduring contributions to the world of art.