Effectiveness and durability of chemical- and laser-based cleanings of lichen mosaics on schists at archaeological sites

Towards safe and effective femtosecond laser cleaning for the preservation of historic monuments

“…This new technique seemed very promising for conservation treatments at a time where heritage objects needed cleaning more frequently [2]. Since Asmus' works, many studies on laser cleaning have been conducted and explored the differences induced by changing the laser parameters such as the emitting wavelength, the laser energy, and the pulse duration on different materials and various contaminants including biological colonization (lichens, algae) [3][4][5][6][7][8][9][10][11][12][13][14], black sulphated gypsum crusts [15][16][17][18][19][20][21][22][23][24], dirt and environmental soiling [25], corrosion products [26][27][28][29][30][31][32][33][34], or graffiti [35][36][37][38][39][40][41][42][43][44][45][46][47]…”