The Missal of Cardinal Angelo Acciaiuoli

Use of yellow pigments

Artists' Materials

Lead-tin yellow is the only yellow pigment used for the images painted within the historiated initials, where it is also employed for highlights over green leaves and mixed with azurite to provide green.

In the letter shapes of the initials themselves and in the border ornamentation, however, lead-tin yellow is substituted on some folios by a lead oxide or by a yellow dye, which in most cases are also mixed with azurite to provide green. These differences suggest that the letter shapes and borders were completed by assistants, while the main artists painted only the images within the initials and the large figures or heads occasionally found in the borders.

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1
Detail of the Cardinal’s portrait under magnification (7.5x), exemplifying the delicate faces with long eye lashes, fine modelling and complex layering of flesh tones that characterise the work of Hand A.
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2
Detail of Christ’s face under magnification (25x), showing the delicate modelling of the flesh tones, with subtle brown shadows and pink highlights over a white base layer. The facial features are defined with reddish brown lines and the eyes are outlined in black. XRF analysis (below) allows the identification of lead white (Pb), vermilion (mercury, Hg) and an earth pigment (iron, Fe) in this area.
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3
Detail of the angel’s mantle under magnification (7.5x). FORS analysis (below) reveals the presence of lead white (absorption band at 1448 nm) and a red dye, probably extracted from insects (absorption maxima at 523 and 565 nm), in the pink portion of the mantle. Additional absorption bands at 1730, 1760, 2310 and 2352 nm are due to the presence of egg yolk used as a paint binder.
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4
Detail of the green folds of Christ’s mantle under magnification (60x). The blue particles which can be clearly distinguished were identified as azurite by FORS analysis. The XRF spectrum (below) reveals the additional presence of lead-tin yellow (Pb, Sn) as the yellow component of this green mixture.

Historiated initial A with Christ blessing and border with Angelo Acciaiuoli’s portrait and arms (Mass for Advent Sunday)

The elegant figures with delicate faces are representative of Hand A. The complex modelling and careful blending of the flesh tones demonstrate his remarkable technical skill (hotspots 1 and 2). He used egg yolk as a binder to paint the figures, both in the miniature and in the border (hotspot 3), and favoured mixtures of azurite with yellow pigments to obtain green hues (hotspot 4).

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