Assessment of cleaning effectiveness for new ecological systems on ancient tempera icon by complementary microscopy techniques

Abstract

The study presents an old icon painted in egg tempera on lime wood, with a poor conservation condition and clogged dirt deposits. The icon is attributed to an anonymous painter of XIXth century and to the neo-classical style of painting. The painting layer was done with only a hand full of pigments, earth colors that were often used in painting the icons from XVIIth to XIXth century in Eastern Europe, that have Byzantine influences. Taking into consideration the nature and the structure of the materials from the upper layers of the painting, affected by deposits of dirt over time, a series of cleaning recipes were studied, using the so called cleaning tests with compatible mixtures of different juices and infusion from indigenes plants, that were freshly done and odorless. A low alkaline 95% ethyl alcohol solution, combined with a few drops of ammoniac 25%, was used as a reference system, due to its compatibility with the greasy deposits found on the polychrome layer and on the wood. The cleaning capacity of the new systems used, in comparison with the standard solution, was analyzed through modern analytical methods of evaluating the degree of cleaning, more exactly by means of visible and UV reflectography, CIE L*a*b* colorimetry by reflection assisted by SEM-EDX and IR spectroscopy.

New Ecological Solutions Involved in the Cleaning of a 19th Century Icon

“…To carry out the washing tests, the 12 supernatants were labelled as in the production protocol, as follows: S1-St John's Wort extract, S2-Sage extract and S3-Licorice extract, followed by the initial extraction conditions (B-Boiling, M-Microwave, U-Ultrasound and E-Room temperature). The washing capacity has been analyzed, similar to with other previous studies [34][35][36][37][38][39], by direct eye observation, visible, and UV reflectrography and by reflection colorimetry, CIE L*a*b*, using the FLICKINER RT Series colorimeter (Reflectance Tintometer). This allowed the chromatic deviation to be recorded directly on the sample, before and after washing.…”

“…From among the main extracts historically used in washing processes, especially in traditional ethnographic practices, we mention the washing of carpets, rugs, and other polychrome artistic fabrics with cabbages, potatoes, onions, and other vegetables. Conversely, the literature is very scant with respect to the cleaning of paintings, with some information available on the use of uncolored vegetables juices [34][35][36][37][38][39][40][41].…”

Scientific investigation of the Imperial Gates belonging to the wooden church from Săcel, Turda County, Romania

“…Along with FTIR spectroscopy and micro-spectroscopy, other analytical methods (XRF [11], Raman spectroscopy [12], DSC, GC-MS [13]) are employed in the investigation and determination of wooden icons, pigments and external wall paintings, the authors of this manuscript having a solid background in the scientific investigation of artworks [11][12][13][14][15][16][17]. Other research groups use analytical techniques as Fluorescence microscopy [20][21][22], TG-DTG-DSC [23], and other spectroscopic techniques in order to investigate as well as authenticate the cultural heritage [24][25][26][27][28][29].…”

Evaluation of Enzyme Agarose Gels for Cleaning Complex Substrates in Cultural Heritage

“…DCA-TEA solution and a 37 • C temperature are commonly used in the field of conservation and no references in the literature provide a warning about interaction with the gel stability. Both the scientific literature [23][24][25][26][27][28][29] and the needs of conservation practice were considered for the testing set up.…”