Bolivian chiriquano masks, carved from toboroche tree wood (similar to balsa) are covered with white (gypsum) and black (wood ash or cinders) decoration. Flaking of the surface layers is a serious problem because every movement of the wood causes further loss. Consolidation was needed and gelatine (2.5 g in water) seemed to give the best results, at least on the white areas. The black areas changed colour and developed a sheen, so that an alternative to the gelatine is being sought. Black and brown algae (chrysophyceae) were found on the surfaces and brushed off. O-phenyl phenol is being tested for use before the gelatine consolidation.