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Frescoes are known to be the most durable form of mural painting. The traditional technique, widely used throughout history, consists of applying water-dispersed pigments on a fresh lime plaster, which hardens through a carbonation reaction. At the beginning of the 20th century, Portland cement was used by some mural artists to obtain similar painting plaster. Although involving different setting mechanisms, cement-based frescoes show the same aspect and durability as lime-based frescoes. Using microstructure characterizations of ancient frescoes (lime- or cement-based) and laboratory reconstructions, this paper offers a description of the mechanisms responsible for the adhesion of pigments and the hardening of surface. [ABSTRACT FROM AUTHOR]

The paper describes the near-surface microstructure of artistic frescoes and compares the traditional fresco technique in which the pigments are applied on a fresh lime intonaco with the more recent technique in which the lime intonaco is replaced by a fresh cement plaster. The study is performed on artworks produced at different periods: one Roman fresco fragment dated from the first century CE, samples from a Renaissance Botticelli fresco and two works by a 20th century artist, HenriMarret, one on a lime intonaco and the other on a cement plaster. A special attention is given to the nature of the pigments used, to their position and adhesion process near the surface and to the colorimetric analysis of the pieces. The characterization of the different objects (performed by optical microscopy, scanning electron microscopy and microanalysis, colorimetric measurements and X-ray diffraction) gives full information on the influence of the artist's technique on the adhesion process and durability of the coloured decoration. It is proved that fresco painting on fresh cement, although considered at the beginning as not as efficient as fresco on lime, leads to a similar mechanism of pigment adhesion and probably to a similar durability. [ABSTRACT FROM AUTHOR]

A set of 33 fragments of lustre-decorated ceramics uncovered during an archaeological excavation in Manises (Valencia, Spain) have been studied. These ceramics were produced in Manises from the 14th to the 18th century. This well-dated set of ceramic shards represents the diversity of Manises lustre production and is a complete time sequence of reference for the technological analysis. Texture analysis of the glazes has been carried out by SEM-EDAX, the inner and outer surfaces of the lustre decorations being analysed with non-destructive ion beams by PIXE and RBS, and also by high-resolution electron microscopy. The results are compared with other lustre productions and the time trend of the microstructures, glaze and lustre composition is analysed. It is concluded that Sn was used to opacify glazes until the beginning of the 17th century and that changes in the lustre microstructure occurred around 1500. [ABSTRACT FROM AUTHOR]

This paper describes microstructural analyses by X-ray portable diffraction and microdiffraction on intentional patina of the bronze museum objects from antique Egypt and the Roman Empire. They bring evidence of the presence in the true black bronze patinas of metallic gold and/or silver presumably as nanoparticles. Three other Egyptian patinas not belonging to black bronze are characterised. Apparent black patination on a Roman scalpel handle is discussed. The discovery of a new patination procedure on Roman artefacts from the Louvre museum is also related, based on intentional high temperature oxidation to obtain a dark patina on a lead bronze object. A presence of lead carbonate cerussite is an important observation. [ABSTRACT FROM AUTHOR]