The art of wax modelling or ceroplastics has an ancient origin, from early Egyptian, Greek and Roman times. It was re-discovered between the 13th - 14th centuries in Florence with the cult of votive offerings; with the advent of Neoclassicism it extended into a more scientific environment, flourishing in the study of normal and pathological anatomy, obstetrics, zoology and botany. On the 7th and 8th June 2019, the 2nd edition of the International Congress on Wax Modelling took place in the University of Padua. The meeting followed that held in September 2017 at the Gordon Museum of Pathology, King's College London. In June 2019, the major institutions related to the art of Wax Modelling met again in Padua; the congress was divided into two study days dedicated to the history, conservation, restoration and technique of this ancient art, which has recently come back into vogue. The event was organised by the University of Padua, under the patronage of CAM - University Centre for Museums, the Academy of Fine Arts of Venice and the National Association of Scientific Museums (ANMS). This conference proceedings: "The Science of Wax" offers a comprehensive overview of many different aspects of wax modelling, including: History (Major Collections), Anatomy and Science (Anatomical/botanical models), Art and Portraiture (Effigies, Portraits, Waxworks, Funeral Masks, Votive Offerings), Conservation and Restoration (maintaining, cleaning, repairing), Techniques and Contemporary Art.