A rare collection of cast votive images (ex-voto) made of beeswax were found in the 1940s behind the cresting of a screen above the tomb of Bishop Edmund Lacey in the Cathedral Church of St Peter in Exeter, England. Some of these fragmentary, aged and brittle waxes, dating from the late fifteenth to early sixteenth centuries, served as the basis to further test the cleaning of dirt and accretions using a Q-switched Nd:YAG laser. Because of the low melting point of the wax, observations on the effects of the heat from the laser to the wax substrate were critical in establishing the efficacy of the cleaning method. Preliminary optical microscopy was used to establish a typology of the waxes based on their condition, colour, and nature of the weathering phenomena. Several techniques were used to characterize the waxes and the surface deposits, including gas chromatography-mass spectroscopy (GC-MS), energy-dispersive x-ray fluorescence (EDXRF) and scanning electron microscopy (SEM-EDS), in addition to simple tests on melting point and hardness that served to help understand the nature, condition and treatment of the waxes. -- ICCROM