The retouching consists in the « optical » / chromatic re-integration of lacunas. The paint is thinly applied and exclusively covering the filled loss, leaving uncovered the original artwork. The colores are accorded to the surrounding area.
In contrast ___ to the general beliefs, the most difficult parts to retouch are the flat-tint areas, the homogeny blue skies along with the deep browns or blacks.
The used products are strictly of different nature than the original paint, guaranteeing their complete reversibility. For example, we will never use oil paint to retouch an oil painting. The removal of our intervention has to be made with solvents also solubilising the original.
Different retouching techniques exist : The illusional inpainting seeking the perfect harmony with the composition. However, the inpaintings stay visible with UV light. The « tratteggio » technique consists in the applying of fine parallel lines of pure colors. View close up, the lines are easily distinguishable, from perspectifs view, the lines blur and the lacunas blend in optically. The pointillist technique bases on the same principal in using dots instead of lines. The retouching with neutral tons, mostly used in fresco restoration, consists in the covering of the lacunas with an even neutral colour in order to highlight the original paint.