Initials from Choir Books

Gold tooling

Artists' Techniques

The intricate designs on the haloes emulate the pioneering punchwork of early-fourteenth-century Sienese artists. Each halo in the Presentation in the Temple displays a different pattern, as does St Laurence’s halo.

The gold backgrounds are not tooled; they were all laid over a thick gesso ground and burnished to a high shine, conveying a three-dimensional impression. Such effect has unfortunately been lost in the two initials which were glued onto cardboard in the 19th century. The individual squares of thin gold leaf, which were carefully laid side by side to form these stunning backgrounds, can be identified in the elemental maps for gold obtained for each of the initials (see layer ‘elemental map Au’).

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1
Detail of the green palm leaf under magnification (60x). Blue particles of two different hues can be seen. They were identified as azurite and ultramarine by spectroscopic methods.
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2
Detail of the Saint’s tunic under magnification (20x). Distinct orange and red highlights can be seen, identified as red lead and vermilion respectively by a combination of spectroscopic analyses including XRF (Pb and Hg in the spectrum below).
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3

Detail of the mosaic gold leaf, outlined with a dark red earth pigment, under magnification (16x). Its shiny aspect and the characteristic peak at 308 cm-1 in the Raman spectrum (below) confirm the presence of mosaic gold.

St Laurence

Historiated initial L from an Antiphoner, 1390s

The initial L belonged to the office of Matins for the feast of St Laurence (10 August) in Corale 19, an Antiphoner made in the 1390s. St Laurence is shown with a book, a martyr’s palm branch and his distinctive attribute, the gridiron on which he was tortured. The image has been attributed to various artists: Don Silvestro dei Gherarducci; his collaborator known as the Maestro delle Canzoni; or the Florentine painter and illuminator Mariotto di Nardo.

It is also possible that the figure of St Laurence and the decorated initial were painted by two different artists; despite general similarities, some differences exist between the pigments used in these two areas. Green hues, for example, were all obtained using a mixture of azurite with a yellow pigment. The palm leaf held by the Saint, however, seems to contain ultramarine as well (hotspot 1). The XRF data also suggest the presence of gypsum in most of the border areas analysed, but not in the figure of the Saint.

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