2 THE ROLE OF CONTROVERSIES

By the end of the 18th century (coincident with the breakdown of extensive, requisite guild or apprenticeship training of artists) the cleaning of paintings began to cause public controversies, which continued across Europe throughout the 19th century. Attacks were made, moratoriums suggested, and commissions appointed in the early days of the Louvre (1790s), the National Gallery, London (1840s–50s), and the Pinakothek in Munich (1860s) (Keck 1984). Advances often follow controversy in many fields.

When the physicist Pettenkoffer proposed his alcohol vapor and copaiva balsam method for regenerating old varnishes in 1863, he hoped this method of minimal intervention would make the need for cleaning obsolete (Keck 1984). The Pettenkoffer method did reduce the number of cleaning controversies during the following 50 years but may have caused undue interaction between paint films and overlying varnishes (Schmitt 1990).

Cleaning controversies crossed the Atlantic Ocean to the National Gallery of Art in Washington, D.C., in the 1970s, and the most recent controversy with passionate press coverage involved the removal of glue and soot from the ceiling of the Sistine Chapel. New methods for formulating cleaning solutions for easel paintings have been published by Richard Wolbers (1988, 1990) and additionally tested by other researchers (see Burnstock and Learner 1992)s.

The lining, or placing of an additional backing fabric against canvas paintings, had not been a matter for public debate until some press attention was focused on this issue following a moratorium on lining declared during a conference at the National Maritime Museum in Greenwich, England in 1974 (Percival-Prescott 1976). The issues were further discussed at the International Council of Museums (ICOM) Committee for Conservation meetings in Venice in 1975, and at another conference on the subject in Ottawa in 1976, which produced a useful bilingual greencovered paperback collection of articles reassessing the lining of paintings (Ruggles 1976), reprinting many of the earlier papers and adding new ones. This focus on the drawbacks of lining was largely coordinated by Westby Percival-Prescott, who reminded conservators that lining a painting places it in a lining cycle or continuum from which it is difficult to escape (Percival-Prescott 1976).

Percival-Prescott took a leadership role and encouraged papers on nonlining approaches or alternatives to traditional wax lining from Gustav Berger, the inventor of the ethylene vinyl acetate adhesive, Beva, which was first introduced in the early 1970s (Berger 1976); Vishwa Raj Mehra, who launched interest in acrylic dispersion lining methods (Mehra 1975); and Robert Fieux, who invented both a new silicone adhesive–Teflon lining fabric, Fabrisil, and a new electrostatic hold system as an alterative to vacuum pressure (Fieux 1976, 1978). Bernard Rabin had published his use of a poly (vinyl acetate) lining adhesive as an alternative to a wax-resin adhesive at the International Institute for Conservation (IIC) Meetings in Lisbon in 1972 (Rabin 1976). Berger and Mehra also discussed and presented suction tables or vacuum envelope systems at IIC, AIC, and ICOM meetings. Suction tables were further developed by others including Bent Hacke and Wieslaw Mitka of Denmark, William Maxwell, Anthony Reeve, Marion Mecklenburg, and his brother Peter Mecklenburg. Many of these materials and approaches are still actively used, and some have been tried and superseded.