*3.11. Retouches*

Many of the (more or less evident) retouches are in the upper part of the miniatures, where the analysis detected, in some cases, the presence of pigments that differed from the original ones. The miniature on f. 31v (Figure 11a) appeared coarsely retouched: a large grey band was apparently added on the original picture, and it was apparent that the sky could have been completely repainted.

Inspection under high magnification supported these hypotheses, since the texture of the blue pigments was completely different from that observed in the original parts (Figure 11b), with blue particles of sub-micrometric size. Micro-Raman signals obtained in these areas are reported in Figure 12 and revealed the presence of phthalocyanine blue, a synthetic pigment available since 1935 (bands at 490, 596, 682, 747, 950, 1140, 1207, 1335, 1443, 1523 and 1569 cm<sup>−</sup>1). Signals of lazurite (bands at 263, 550 and 1092 cm−1), possibly pertinent to the original layers, were also detected.

**Figure 11.** (**a**) Miniature on f. 31v. Retouches in the upper part of the picture and in the hut are visible. (**b**) Micro-photography (80×) of the blue sky close to the grey retouch.

**Figure 12.** Raman signals recorded from the blue sky on folio 31v (**top**), from natural ultramarine spread on parchment with gum Arabic (**middle**) and from phthalocyanine blue spread on parchment with gum Arabic (**bottom**).

On examination, the grey band was attributed, via XRF, to a layer of powdered silver. Besides silver signals, XRF revealed here the presence of titanium, which points to the use of another modern pigment, i.e., titanium white (TiO2). The lack of any micro-Raman signals from this compound, which is a strong Raman scatterer, suggests that titanium white was used to mask the underlying picture prior to the laying of silver powder which was presently darkened by weathering.

A similar rough intervention is visible on f. 46r (Figure 1h), where a grey band was added to the lower part of the sky; here again, a possible intervention on the sky itself was suggested. However, despite the various macroscopic similarities between the two restoration interventions on ff. 31v and 46r, instrumental investigation did not give us any incontrovertible evidence that they were carried out at the same time by the same restorer. In fact, glittering silver particles observed in the grey band under the microscope on f. 31v appeared significantly coarser than those observed on f. 46r (Figure 13).

**Figure 13.** (**a**) Micro-photography (40×) of the grey bands on f. 31v. (**b**) Micro-photography (40×) of the grey bands on f. 46r. Different dimensions of the silver particles are evident.

XRF confirmed that silver was employed in both interventions, but it did not show the presence of titanium on f. 46r, thus pointing to a different silvering technique. With regards to the blue pigments, the Raman investigation carried out on f. 46r indicated the presence of ultramarine blue, whereas the presence of phthalocyanine blue found on f. 31v was not detected; also, the FORS spectra pointed to the presence of azurite and ultramarine, i.e., the same pigments originally employed by Antoine de Lonhy. Moreover, under the microscope the sky of the miniature on f. 46r presents a micro-texture resembling that of other original parts painted with the same pigments. These results suggest that the restorer who painted the silvered band around the Cross on f. 46r spared the sky above it.

A peculiar case is the dark vaults above the main characters in the funerary scene at f. 71v (Figure 1j). Here, the morphology of the silver particles and the absence of titanium seems similar to those employed in retouches on f. 46r. However, the XRF analysis revealed the presence of gold, indicating the original presence of a golden architecture, possibly similar to that still visible in the miniature on f. 1r (Figure 1a) but covered at a later date with silver that now appears darkened.

The analysis of the sky also did not highlight any proof of retouched areas, suggesting that the sky here was spared by the restorer. The same holds for other miniatures: no clues of the use of modern materials emerged after the evaluation of micro-textural and compositional characteristics, revealing the sole presence of blue pigments that are fully comparable, from a compositional and morphological point of view, with the original ones.

Retouches on browns at ff. 24r and 31v (Figure 1c,e) are clearly visible to the naked eye. FORS spectra from the dark brown interior part of huts yielded evidence of iron oxide pigments, similar to those obtained from other brown untouched areas present in other folios. The XRF analysis of the repainted areas, however, showed lower iron signals with respect to the original iron oxide pigments; moreover, in all the retouched areas, signals of chromium and cobalt, very similar in intensity, were detected, whereas in the original brown pigments these elements were undetectable. These data strongly suggest that ff. 24r and 31v were modified by the same hand; unfortunately, a strong fluorescence band prevented the collection of micro-Raman signals which could have better elucidated the nature of the brown pigment.

### **4. Discussion**

As highlighted by the results of the scientific investigation, the palette used by Antoine de Lonhy for this *Book of Hours* is rich and variegate (Table 2). The results also show how the different colourants were used in the decoration of the book, which may give further information and allow a comparison with the palette from the coeval manuscripts.


**Table 2.** The palette identified in the decoration of the *Book of Hours*.

<sup>1</sup> possibly related to retouches.

#### *4.1. The Hierarchical Use of Colourants*

It emerges that—for blues, reds and yellows—different colourants were used for the same hue, and some kind of hierarchical scheme can be highlighted for the miniatures painted by Antoine de Lonhy. We are not talking here about the hierarchy of *colours*, an aspect on which there is a very wide coverage [32,33], but rather the hierarchy of the *colourants* inside the different colours. To investigate this topic, we can start from the commercial aspects discussed by S. Nash [34] in her study on the proofs of payment for artistic materials supplied to the court of the Dukes of Burgundy from the 14th to 15th centuries, which are now conserved in the Archives Départementales de la Côte-d'Or in Dijon (France).
