10 CONCLUSION

IN THE RELATIVELY SHORT PERIOD since their invention in the 1920s, pressure-sensitive tapes have swept the world market. They are inexpensive, universally available, and convenient to use. These factors make them seem ideal for a variety of applications to archival materials and art on paper. However, time and experience have shown that pressure-sensitive tapes on paper are disfiguring, damaging, and difficult—sometimes impossible—to remove. Even the recent development of so-called archival tapes has not solved these problems from a conservator's viewpoint.

The success rate for tape removal is much greater now than it was fifteen years ago. This progress can be attributed in part to increased understanding by conservators of the aging behavior of pressure-sensitive tape systems and the properties of organic solvents. It is also due to the availability of improved equipment and to the informed sharing of effective techniques. The three approaches to pressure-sensitive tape removal outlined above summarize the methods most frequently employed by the paper conservators in the Library of Congress Conservation Office. There are others that are equally effective. However, as long as pressure-sensitive tapes are available on the market, conservators can expect to be challenged by tape removal problems with elusive solutions.