Lacquerware Pigment Identification with Fixed and Mobile Raman Microspectrometers: A Potential Technique to Differentiate Original/Fake Artworks

Abstract

(FT) Raman spectroscopy is used for the first time to identify pigments used in 19 th & 20 th century Japanese and Vietnamese Lacquerwares. IR spectroscopy is used to assess the Lacquer matrix. Different operative conditions and parameters were experimented with on a limited number of lacquerwares in order to determine the optimal procedure for the identification of pigments/dyes as potential chronological or technological markers. The test was then performed in the collector's rooms with a mobile Raman set-up. Different pigments (vermilion, Prussian Blue, Naples Yellow, Phtalocyanine Blue, anatase, rutile, chalk, carbon black) were identified despite a strong fluorescence and a rapid degradation of both pigments and binder under increasing laser power. Better spectra were obtained on older lacquerwares.

On‐site Raman study of artwork: Procedure and illustrative examples

“…All of them use the dispersion of a phase with an optical index different from the matrix. The main opacifiers are tin oxyde (cassiterite), calcium silicate (wollastonite), calcium phosphate, and lead arsenate . Raman microspectrometry can very easily detect lead arsenate, thanks to the high number of electron involved in the As─O bond.…”

“…Moreover, the need to keep precious items in secure areas led to the use of mobile and contactless instruments, whereas the ongoing miniaturisation of laser, spectrometer, detectors, and computer [8] led to the popularisation of Raman mobile set-ups to study Cultural Heritages. [7,[9][10][11][12] The collection of Raman data for paintings is more complex: paintings are unique and fragile, which limits their handling, and the pictorial layers are generally covered with one or more layers of varnish, a material that gives rise to strong fluorescence phenomenon covering Raman signal. [13] Consequently, section analyses of (micronic) scales obtained by sampling or collected after simply falling during handling or restoration is needed.…”

An investigation of a unique group of painted silk banners from a Polish collection

“…In conservation science, the increasing need for non‐destructive investigations is a major issue, as sampling is in most cases restricted in view of the value or the uniqueness of the object . The use of Raman spectroscopy for non‐destructive characterization of art objects has become central in the field of heritage science . This study focused on the combined use of Raman spectroscopy and X‐ray fluorescence spectrometry (XRF) performed using portable systems to increase the knowledge of the pigments and materials used in the studied banners.…”

“…[4,5] The use of Raman spectroscopy for non-destructive characterization of art objects has become central in the field of heritage science. [6][7][8] This study focused on the combined use of Raman spectroscopy and X-ray fluorescence spectrometry (XRF) performed using portable systems to increase the knowledge of the pigments and materials used in the studied banners. The portable equipment allowed performing in situ analysis in the museum storage rooms.…”

Raman Identification of Pigments in the Work of the Chilean Contemporary Visual Artist Ignacio Gumucio

“…Nevertheless, its meaningful disadvantage still lies in the formation of undesirable fluorescence, which is an accompanying phenomenon of measurements of diverse materials and which is very difficult to forecast. The main applications of Raman in heritage studies concern the identification of pigments and dyes on various support materialities [12][13][14] . Pigments together with binders and fillers give important information about artists, artistic schools or technological evolution.…”