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• ATR-FTIR spectroscopy is used to assess the condition of historical silk samples. • Evaluating the conditions of historical textiles guides conservation and preventive measures. • Differentiation between original and later interventions is also possible. • Visual, bivariate and multivariate methods are used to evaluate the data. • Spectral evaluation reveals deterioration markers, explained according to literature. Understanding the conservation condition of historical silk yarn allows to define appropriate storage, care and display of historical silk collections. This paper discusses the characterisation of silk fabrics from a collection of traditional Japanese samurai armours which date back from the 16th to the 20th century (Morigi Collection, Museo delle Culture, Lugano, Switzerland). An analytical protocol to assess silk fabrics conditions was defined, based on microinvasive ATR-FTIR spectroscopy. In particular, the amide I and II region was studied in order to extrapolate the conformational information about silk proteins. According to literature, this kind of information can be related to different degradation stages. A linear correlation was found between the amide I and the amide II shifts, allowing to assess the silk fibre condition. Along with this bivariate approach based on intensity ratios, a multivariate approach based on Principal Component Analysis was also applied to ATR-FTIR spectra. This allowed to group together silks with the same state of preservation. The findings of this research offer a valuable method to researchers and conservators to identify the most damaged textiles; the differentiation between original and restoration materials was also possible in some cases. [ABSTRACT FROM AUTHOR]

• First characterisation of pigments used in coloured Japanese photographs. • Non-invasive infrared analysis identified various pigments used to colour the photos. • Western pigments, traditional Japanese dyes, and aniline colours were identified. • Use of a beeswax-based varnish on the photos surface was revealed. This paper describes the first systematic analysis of 19th century Japanese coloured photographs. This unique Japanese technique followed the diffusion of photography taken up by Westerners. The photos were coloured by the painters of the School of Yokohama from ukiyo-e prints ateliers and were sold to travellers returning home as a souvenir from Japan. Although there are several museum collections throughout the Western world, this artistic technique has never been thoroughly investigated, due above all to the fragility of the artworks. In this study 22 photographs and a photo album cover from the Museum of Cultures (Lugano, Switzerland) were analysed by non-invasive infrared spectroscopy in order to identify the painting materials. A preliminary survey was carried out on reference pigments used in Japan in the 19th century, some of which are the same as those used in Western Europe, but many are particular to the Japanese school of arts. The reference pigments were analysed after extraction procedures taken from traditional recipes. Modern pigments such as "aniline colours" were also considered. The results provided insights into the painting materials, for example identifying Prussian blue, gofun, yamahaji , enju , shio , and rhodamine. The data confirmed the use of albumen paper and detected the application of a beeswax-based varnish for conservation purposes. [ABSTRACT FROM AUTHOR]