Modern Procedures Used in Cleaning Old, Illegibly and Blackened Icons

Abstract

In order to restore the original aesthetic aspect, to improve the state of the age patina and of the gold halo, similar processes are required. The cleaning process is one of the most important aspects for an artwork and is considering a series of deteriorations and degradations, like dirt deposits (clogged or unclogged) opalescent varnish, colors blackening, burns, blisters, gaps (missing ground, painting layer or varnish). This step in the restoration process includes physical and mechanical proceedings like dusting (with a vacuum), brushing (with a brush), scraping (with a scalpel), removal or polishing etc. The scalpel and the milling process are rough unconventional means that are used only in exceptional cases. The wet cleaning of dirt includes classic washing processes, with water or other complex systems of organic solvents (emollients, surface additives or surfactants, mixtures of solvents). Cleaning the clogged dirt deposits with unconventional methods can be done by means of electronic laser, ion and thermal exchange or ultrasounds. Laser cleaning is often used in removing unwanted dirt deposits from different layers of the art piece. A lot of attention goes towards the controlled elimination of the exterior protection layer (varnish), which can be photo- degraded and oxidized by atmospheric exposure. Visual analysis, with enlargers (OM, SEM, AFM etc.) combined with transmission or penetration techniques (radiography, endoscopy, X-ray diffraction etc.) provides information on the superficial structures of the art work. In order to determine the modifications of the desiccant oils, SEM was used to observed the changes in the morphology of the oil painting layers. Gas chromatography/mass spectrometry (GC/MS) can be used to detrmine detergent residues on the painting layer.

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].…”