Paint ablation process vs. different laser wavelengths for 18 diverse spray paints used for graffiti on the monuments and historical mansions

Some diverse spray paints, used for graffiti on the monuments and historical mansions, were selected and chosen. These paints are ones common used by some uncivil young peoples to produce graffiti on many monuments and historical mansions. These paints were sprayed on a stainless steel square plate substrate (30x30mm) and left to dry outdoors for 3 days. Then thickness measurements of each painting on these samples were carried out. Moreover each of the 18 paintings was subjected to reflectivity (absorption) measures by using a reflectance spectra in the range from 2500 to 300 nm. So many plots were recorded by an UV-VIS-NIR Cary 5 (Varian) spectrophotometer using a scanning rate of 600.00 nm / min, a data interval of 1,000 nm and average time of 0.1 s. By using the same technique the restricted range from 300 to 1200nm were investigated for a close, interesting and precise scanning. All this results much more useful and interesting as it can furnish many experimental information on the per cent absorption of a data laser wavelength for a specific spray paint , identified by a RAL (Reichsausschuss für Lieferbedingungen) Code for a normalized colour scales (RAL 840 HR for opaque colours and RAL 841 GL for brilliant colours). This information were not possible to obtain on the scientific literature as well as by some paint manufacturers, so it was necessary and useful to test for a better comprehension of the laser ablation process as well as for the possible chance of success. The works are still in progress.