Just published: A. Cosentino “Effects of Different Binders on Technical Photography and Infrared Reflectography of 54 Historical Pigments” International Journal of Conservation Science, 6 (3), 287-298, 2015.


Effects of Different Binders on Technical Photography and Infrared Reflectography of 54 Historical Pigments (696 downloads)

Effect of different binders

Technical Photography (TP) is the collection of broadband spectral images in the range 360 – 1100 nm collected with a modified digital camera: visible (VIS), ultraviolet fluorescence (UVF), reflected ultraviolet (UVR), infrared (IR), infrared fluorescence (IRF) and infrared false color (IRFC). An InGaAs camera is sensitive to the 900-1700 nm range and provides infrared reflectography (IRR) images. It was previously shown that all these techniques used together allow a tentative identification of pigments laid with gum arabic. While the identification must be confirmed with analytical instruments, this flowchart method allows a fast and low-cost preliminary examination of polychrome works of art.  This paper discusses the effects that other binders (egg tempera, linseed oil and fresco) can have on technical photos and on infrared reflectography images of 54 historical pigments. It is shown that only the UVF photos are considerably affected by these binders. The strong fluorescence emission of egg tempera and linseed oil dominate the UVF photos while the binders do not consistently affect the other technical photos, IR, IRF, IRFC and IRR.  This study confirmed the validity of this comparative method for the tentative identification of pigments laid with the most common binders used on works of art.

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’.

Read our other papers on Technical Photography

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Read our other papers on Pigments Checker

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