In the early 1990s, the Schlurfer (from the German schlurfen, to slurp) was developed for dirt removal from sensitive modern art paintings by the German conservator Winfried Heiber, later professor at the Academy of Fine Arts in Dresden. It was initially used for unvarnished paintings, where the traditional mechanical methods of water-based cleaning (such as rolling, wiping, and swabbing with wet soft sponges, tissues, or cotton swabs) led to pigment loss, color changes, and microdeformations. In contrast, a water treatment with the Schlurfer was able to reduce the mechanical impact to the extent that no paint damage or negative effects could be observed.