A new free online FORS spectra database of pigments is available. FORS (Fiber Optics Reflectance Spectroscopy) is a low-cost spectroscopy and it is used to identify pigments on art works. CHSOS tested an innovative miniaturized and affordable spectrometer and created the spectral database. This new paper “FORS spectral database of historical pigments in different binders” introduces the database of 54 historical pigments laid with 4 different binders, gum arabic, egg tempera, linseed oil and fresco.  The FORS spectra can be downloaded in CVS format from the e-conservation journal or from the CHSOS website. This database is of great help for pigment identification purposes since it provides for the first time, the additional possibility to freely download all spectroscopic data. This is likely to be a well welcomed opportunity for all the other FORS researchers in art conservation.


pigments checker v2 vsPigments Checker is for photographers, conservators and scientists interested in technical documentation of paintingss. It has 54 swatches of historical pigments designed for infrared photography, ultraviolet photography and other technical photographic methods for art examination. Check it out!

Pigments Checker is a collection of 54 swatches of his­tor­i­cal pig­ments that have been applied using gum ara­bic as a binder on a cel­lu­lose and cot­ton water­color paper, acids and lignin free. This paper is not treated with opti­cal bright­en­ers, it’s slightly UV flu­o­res­cent, and it reflects IR. Two cross-hair lines, 0,2 mm (ver­ti­cal) and 0.4 mm (hor­i­zon­tal) are printed on each swatch of paper before the appli­ca­tion of paint, in order to have a means to eval­u­ate the pig­ments’ trans­parency in the IR and IRR imag­ing. Among all the pig­ments and their vari­eties ever used in art these pig­ments col­lec­tion select the most used ones from antiquity to early 1950’.


The database aims to provide a knowledge base for the evaluation of the effect of different binders on the pigments’ spectral features. CHSOS confirmed the effectiveness of the FORS system used for the non‐invasive identification of pigments in different binders. This system is small, low cost and the acquisition is rapid. It makes it well adapted to the specific needs of professional art examination in the field. This new database is a very useful and helpful addition to the already created databases of reflectance spectra existing on line. Researchers working in the field of Cultural Heritage Science can significantly benefit from the added possibility to freely download all spectroscopic data that is provided for the first time, and use it as a powerful tool for pigments identification purposes as well as to evaluate how different binders influence the spectral features of the pigments.

I need to thanks GHT Photonics srl,  the Italian representative of Ocean Optics, which kindly lent to CHSOS the FORS system.

 

FORS pigments reflectance spectroscopy

A. Cosentino “FORS spectral database of historical pigments in different binders” e-conservation Journal 2, 57-68, 2014.

FORS system pigments identification

Miniaturised FORS system (from left to right): halogen lamp, USB4000 spectrometer and integrating sphere. On the background, the “pigments checkers” , boards of pigments laid with egg tempera, linseed oil and gum arabic.

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