Laser cleaning is the only cleaning method which truly does deep cleaning. All other methods just remove part of the dirt. Also, polution on rollers consists of pigments and polymers. Most methods do remove pigments but they do not remove polymers. Polymers can only be removed by vaporation (by burning the dirt). This is exactly what the laser achieves: it burns the dirt. After laser cleaning the surface tension of the roller is restored to its maximum and functions like a new roller.