_Applied_  
_sciences_  
_Inspits into [PERSON]'s Terracotta Monument to Cardinal [PERSON]: Raw Materials and Technologies_  
**[PERSON] 1,*(c)**, [PERSON] 1, [PERSON] 1 and [PERSON] 2  
1 CNR-ISPC, National Research Council--Institute of Heritage Science, Via Madonna del Piano 10, 50019 Florence, Italy; emma.cantisani@cnrit (E.C.); silvia.vettori@cnrit (S.V)  
2 CHART, Cultural Heritage and Archaeometric Research Team, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark SDU, Campusvej 55, 5230 Odense, Denmark; [EMAIL_ADDRESS]  
* Correspondence: [EMAIL_ADDRESS]  
Footnote 20: https://parts compared to the polychrome ones. The conjunction of the tiles is visible only in a few areas. It can, therefore, be hypothesized that the artist did not produce one tile at a time, but rather produced them as longer slabs. After having engraved them, he most likely cut them according to the outline of the design in hidden points. However, the most peculiar detail of this artwork remains the application of the golden foil. Starting from the conservators' indications, three main hypotheses can be suggested for its manufacture: (i) the use of cold-gilding technology; (ii) the presence of a \"_luster_\", a decorative metallic film applied on the surface of the glazed ceramics, obtained by a low-temperature (below 650 \({}^{\circ}\)C) controlled reduction of copper and silver compounds; (iii) what is called the \"third firing\" technique [1; 2; 3; 4]. This latter technique has been used since ancient times, and it was applied above all to porcelain. The term \"third firing\" refers to the third firing event that is applied to an object or a tile that has already undergone two phases: (i) a first firing of the support; (ii) second firing of the glaze or glazing, to subsequently add the decorations in the multiple techniques. Already at the first step, the ceramic could be painted with the underglaze technique which guarantees a brilliant and unalterable result over time thanks to the subsequent vitrification. In the case of \"third firing\" process, the method of decorating is the overglazed technique. The powder colours or gold foil are blended with the addition of a fluid medium and are applied with a brush on the ceramic object. The latter is then subjected to a cooking of approximately 750-900\({}^{\circ}\). During the firing, on-glaze materials melt with the vitreous coating of the ceramic, becoming one with it.  
Figure 1: The Tomb of Bishop [PERSON] by [PERSON]. Santa Trinita Church, Florence, Italy.  
Numerous scholars have dealt with archaeometric analysis of the works of [PERSON] [5; 6; 7; 8; 9; 10; 11; 12; 13; 14]. Many of these works were focused mainly on the characterization of glazes and raw materials such as the terracotta body, but no archaeometric study was previously performed on the artist's production, characterised by this experimental technique of gilding.  
The [PERSON] monument has been studied in detail with regard to the historical value and as a piece of artwork [1; 4; 15; 16], but no in-depth investigations have been made from an archaeometric point of view. In particular, as far as we know, there are currently no works dealing with this particular gilding technique. Normally, the golden decoration visible on other [PERSON] masterpieces, are manufactured by spreading the leaf gold with a binder, following the traditional \"cold gilding\" technique as in the \"Altman Madonna\" at the Metropolitan Museum, or in the \"Virgin and Child\" (called the Genoa Madonna) at the Detroit Institute of Arts.  
Starting with these issues, the present study focuses first to examine and characterise the raw materials and the procedure to realise the glazed tiles, then to define the unique technique employed by [PERSON] to decorate the golden tiles since as far as we know this technique is a unicum in the production of the artist.