Novel Applications of the Er:YAG Laser Cleaning of Old Paintings

Abstract

Focuses on the use of Er:YAG laser cleaning technique for the removal of unwanted and/or degraded materials from both a large series of reference standards (overpainting, varnishes, patinas, and restoration materials) that simulate the layering of old paintings, and also examples from old paintings. A series of diagnostic controls (optical microscopy, scanning electron microscopy, Fourier transform infrared, gas chomatography-mass spectrometry, and topographic techniques) were designed to study the effects of the laser radiation on the surface components, including morphological, optical, and chemical examination. The most significant results show that an effective thin-layer removal of about 90% is obtained by submitting the painted surfaces to the laser exposure, while the remaining cleaning is rapidly accomplished safely by applying mild solvents or aqueous methods. Consequently, possible interference with the original substrate can be noticeably minimized. No degradation compound induced by laser energy was formed. The laser cleaning procedure applied on an oil painting on canvas, The Death of Adonis (17th century), and on a tempera panel painting, St. Nicholas and St. Just by Domenico di Michelino (15th century), shows that the surfaces cleaned by this system exhibit a morphology quite similar to that obtained by traditional cleaning methods.