FORS (Fiber Optics Reflectance Spectroscopy) has been used for art examination and art conservation for at least 2 decades for identification of pigments
Pigments 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’.
I was following the development of a series of miniaturized spectrometers by Ocean Optics, leader in innovative optical systems. As for my daily work in on-site art examination I’m always looking for new low-weight solutions and these instruments looked as exactly what I was searching. I wrote to Ocean Optics and they put me in contact with their Italian representative, GHT Photonics, based in Padua, the town where Giotto decorated the Scrovegni chapel, one of his most famous frescoes. They were helpful to arrange a loan and let me have a look at their low-cost FORS system in the “Cultural Heritage Science Open Source” lab in Sicily. I was so delighted by this system. Ocean Optics has made a kind of revolution in spectroscopy: miniaturized and low-cost spectrometers, really, really affordable.
This opens possibilities to researchers and private professionals which can now introduce optical spectroscopy in their workflow. Indeed, with just one spectrometer it is possible to run a different number of spectroscopic methods, just changing lamps and probes. The same spectrometer can be used for reflectance spectroscopy and transmittance spectroscopy as well as fluorescence spectroscopy. So, just purchasing one spectrometer and using some of our geekeness with optical tools we can run a number of art examinations. Should I use one word to describe this system, I would say FUN!
I have been testing this FORS system on my collection of historical pigments and on a number of art objects in Sicily and I’ll provide some results in the following posts. This video shows some of the art examined.
 T. Cavaleri, A. Giovagnoli, M. Nervo “Pigments and mixtures identification by Visible Reflectance Spectroscopy” Procedia Chemistry 8 ( 2013 ) 45 – 54.
 E. Cheilakou, M. Troullinos, M. Koui “Identiﬁcation of pigments on Byzantine wall paintings from Crete (14th century AD) using non-invasive Fiber Optics Diffuse Reﬂectance Spectroscopy (FORS)” Journal of Archaeological Science 41 (2014) 541-555.
 M. Picollo, M. Bacci, A. Casini, F. Lotti, S. Porcinai, B. Radicati, L. Stefani “Fiber Optics Reflectance Spectroscopy: a non-destructive technique for the analysis of works of art” Optical Sensors and Microsystems: New concepts, Materials, Technologies, edited by Martellucci et al., Kluwer Academic / Plenum Publishers, New York, 2000
 Scientific examination for the investigation of paintings, AA.VV.Edited by D. Pinna, M. Galeotti, R. Mazzeo, 2009.
 M. Gulmini, A. Idone, E. Diana, D. Gastaldi, D. Vaudanc, M. Aceto “Identiﬁcation of dyestuffs in historical textiles: Strong and weakpoints of a non-invasive approach” Dyes and Pigments 98 (2013) 136-145.[ws_table id=”7″]