The Reichenau Epistolary

Purple dye

Artists' Materials

The purple background of many of the folios reveals the artist’s intention to evoke the prestigious purple codices of the Roman and Byzantine Empires, which were dyed with expensive Tyrian purple extracted from Murex sea snails.

Here, however, the illuminator used a more affordable colourant, a purple dye obtained from lichens, probably orchil (Roccella tinctoria). A mixture of the same dye with lead white provided the lavender hue visible in some folios.

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1
Detail of the unevenly painted purple-dyed background under magnification (60x). The FORS spectrum (below) shows the characteristic maximum absorbance of orchil at c. 597 nm.
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2
Detail of a turquoise area under magnification (60x), showing blue and white pigment particles. The FORS spectrum (below) shows the characteristic absorption bands of azurite (at 1493, 2280 and 2351 nm) and lead white (1441 nm).
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3
Detail of a blue trilobed leaf under magnification (60x). Particles of blue pigment can be distinguished along with impurities of other colours, suggesting the natural origin of the pigment. The Raman spectrum (below) shows the characteristic peak of lapis lazuli at 541 cm-1.
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4
The Raman spectrum of an orange area shows the characteristic peaks of both red lead (116 and 543 cm-1) and massicot (138 and 283 cm-1). The identification of massicot, a natural mineral which is roasted to obtain red lead, supports the synthetic origin of this pigment.

Framed panel with half-page ornamental initial E (Good Friday-Easter Sunday)

The gold letters are set against a background painted unevenly in a lichen-derived organic purple, most likely orchil (hotspot 1). The same purple mixed with lead white provided the pale background of the lower portion of the initial. The striking turquoise in the upper portion was identified as azurite lightened with lead white (hotspot 2). The blue details were painted with the fabulously expensive ultramarine, still scarce in this early period (hotspot 3). The bright orange areas were painted with red lead, which contains traces of massicot, a lead oxide roasted to produce red lead. Indicating an incomplete roasting process, the massicot reveals that the orange pigment was artificially made for this manuscript, rather than sourced from naturally occurring minium (hotspot 4). The combination of mineral and organic, naturally available and specially manufactured, local and imported materials is a measure of the sophisticated tastes and advanced technical skills available in 10th-century Reichenau.

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