Laser Versus Conventional Cleaning Methods: Do the Costs Outweigh the Benefits?

Art Conservation B.V. participates in the PaReLa project, a European Commission funded, cooperative research project entitled ‘Paper Restoration using Laser Technology’ (EVK4-CT-2000-30002). The purpose of this project is to develop a laser system suitable for the accurate, efficient and safe cleaning of paper objects. Other participants include BYB, Guillet, Hai Yen, Susan Corr, TNO, BAM, ICN and FORTH. Our paper discusses the research outcomes and the feasibility of this method in practice. For research purposes we aged a great number of samples, plastered with different types of tape, in special ovens. Next we carried out experiments using various types and doses of laser light to determine how the adhesive residues can best be removed. It appears that the laser system can yield excellent results. However, we feel that, in practice, requirements may well differ from those set in the PaReLa project. In order to appreciate the added value of the laser cleaning, we also tested conventional methods. Thus, our paper also provides an assessment of established methods to remove marks, inks, and adhesive discolorations. It is well known that these methods have several disadvantages. For instance, the use of solvents may be harmful to both the restorer and the object, and there is a risk of tidemarking in the long run. Yet the conventional methods are often preferred because they are more familiar to restorers, and, not unimportantly, because they are cheaper. Finally, in a detailed case involving removal of tape and remains of glue from a film poster, we will compare laser treatment and a conventional method. In conclusion, laser cleaning has benefits over other, conventional methods. However, as it proves to be more expensive, it is little used in practice. We at Art Conservation indeed wonder whether the researchers’ views on today’s conservation practices are realistic enough.