Comparison of cleaning methods for stained glass windows

Any cleaning process for stained glass windows has to consider the effectiveness of the treatment but also the potential damage for the art object. A variety of mechanical and chemical methods is currently used in restoration practice. The most effective ones are criticized because of their long-term risks. Therefore, an interdisciplinary research project, carried out in Germany and funded by the "Deutsche Bundesstiftung Umwelt (DBU)" had explored the possibilities and limits of lasers for cleaning glass windows. At previous LACONA conferences the Excimer Laser equipment and results from the research project have been presented. This contribution puts the cleaning experiments in a broader context, by comparing lasers with conventional techniques. Scientific and practical aspects will be discussed, focussing on the removal of crust and aged polymers.