The desire to replace ivory and copy this treasured and at the same time ethically unjustifiable material is nothing new. Nevertheless, all commercially available replicas are deficient in the most important characteristics, especially the optical properties. Additionally, most of these materials are only available in bulk and not in the desired shape. Carving a replacement part out of either ivory or a bulk substitute can take a lot of time and is in most cases unaffordable.

In the course of this interdisciplinary research project of the TU Wien, Cubicure GmbH, The Department of Art and Preservation of Historical Monuments of the Archdiocese of Vienna and the restoration studio Addison KG, a 3D printable ivory substitute called “Digory” was developed to mimic not only the aesthetic but also the mechanical and haptic properties of ivory. The color and translucency are adjustable to resemble the original shade of individual ivory parts that are to be replaced. Also, the density and hardness values of Digory are comparable to ivory. With proper artistic post-processing the resemblance to natural ivory is additionally enhanced (Figure 1).