Mineral pigments such as ochres and earths have been always searched and used in human history alone or in combination with other colouring materials for the preparation of red, yellow, blue, green and black powders for paintings. At times, artists used to mix two or more pigments in different ratio, to enrich the chromatic palette, to limit the use of more expensive pigments and to obtain different desired colour hues. This practice has been found recurrently in Apulian paintings, both from rupestrian contexts and historical masonry buildings, in which precious pigments were replaced by well pondered mixes of ochres, earths and other common materials. This research aims to create a library, as reference tool for the study of mural paintings, by collecting the results of non-invasive analytical methods carried out on specifically created pictorial layers composed of pure pigments and locally frequent recipes. For this purpose, laboratory replicas of different colours, by using 18 pigments by both fresco and lime painting techniques and 37 locally recurrent colour mixes, composed of two or more pigments, have been prepared. Pigments were kindly offered by Kremer Pigmente GmbH & Co. KG (Aichstetten, Germany). Before to be applied, pigments were characterised by X-ray Powder Diffraction analysis (XRPD). For the characterisation of replicas a non-invasive approach has been adopted. Portable digital microscopy equipped by polarized light filter, colorimetry test (in CIEL*a*b* coordinate system), Fiber Optic Reflectance Spectroscopy (FORS) and X-ray Fluorescence Spectroscopy (XRF) have been used as diagnostic techniques for the identification of pigments in replicas. A remarkable database on mixes widespread in the Apulian wall paintings has been produced. This approach has proven to be sustainable in terms of measurement speed and effectiveness, but above all in terms of data comparison with wall paintings of other and farer contexts.
A library for the Apulian (Italy) wall paintings: a non-invasive approach for the study of mineral pigments and their mixing
Marina Clausi;Giacomo Eramo;Giovanna Fioretti
;Elisabetta Longo;Alessandro Monno;Daniela Pinto;Gioacchino Tempesta
2022-01-01
Abstract
Mineral pigments such as ochres and earths have been always searched and used in human history alone or in combination with other colouring materials for the preparation of red, yellow, blue, green and black powders for paintings. At times, artists used to mix two or more pigments in different ratio, to enrich the chromatic palette, to limit the use of more expensive pigments and to obtain different desired colour hues. This practice has been found recurrently in Apulian paintings, both from rupestrian contexts and historical masonry buildings, in which precious pigments were replaced by well pondered mixes of ochres, earths and other common materials. This research aims to create a library, as reference tool for the study of mural paintings, by collecting the results of non-invasive analytical methods carried out on specifically created pictorial layers composed of pure pigments and locally frequent recipes. For this purpose, laboratory replicas of different colours, by using 18 pigments by both fresco and lime painting techniques and 37 locally recurrent colour mixes, composed of two or more pigments, have been prepared. Pigments were kindly offered by Kremer Pigmente GmbH & Co. KG (Aichstetten, Germany). Before to be applied, pigments were characterised by X-ray Powder Diffraction analysis (XRPD). For the characterisation of replicas a non-invasive approach has been adopted. Portable digital microscopy equipped by polarized light filter, colorimetry test (in CIEL*a*b* coordinate system), Fiber Optic Reflectance Spectroscopy (FORS) and X-ray Fluorescence Spectroscopy (XRF) have been used as diagnostic techniques for the identification of pigments in replicas. A remarkable database on mixes widespread in the Apulian wall paintings has been produced. This approach has proven to be sustainable in terms of measurement speed and effectiveness, but above all in terms of data comparison with wall paintings of other and farer contexts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
