A New Method for the Restoration of Palaeontological Specimens Mounted in Canada balsam

Abstract

Many museums contain slides mounted with Canada balsam. If this resin is poorly prepared, it can become crazed. Examples can be found within the British Type Graptolite Collection at the Natural History Museum, London. These are delicate dendroids prepared using the transfer technique. A search of the available literature and communication with museum workers highlighted suggestions for methods to rescue the cracked slides. These methods were tested, and the most suitable method proved to be a double transfer technique utilising carbowax. This technique may be used to rescue any specimen which is mounted in Canada balsam and which possesses an exposed surface. It is particularly important for the conservation of fragile specimens.