AIC's 52nd Annual Meeting

With the second industrial revolution (1870-1914), materials typically used in the making of art underwent a substantial transformation in order to meet new expectations that would fulfill the needs of the artist. In sculpture, traditional processes were used until the very end of the 19th century. Traditionally, softer materials such as wax or clay would be used for producing the original sculpture models by the artist, that would then be transferred into a more durable material.

The sculpture models made in clay were inconvenient in that once the clay would dry the artist could not make modifications to the model. Using wax also proved problematic, as it does not resist high temperatures very well and also lacks ductility. By the mid 19th century there are records of recipes that were being developed to modify waxes in order to impart more ductile proprieties. These hand-mixed, homemade formulas came to be known as modern modeling materials. However, it is not until the end of the 19th century that modeling pastes were being developed in a more industrial manner.

The materials used to form these original positive models were often recycled and repurposed for other sculptures after being cast in plaster or transferred directly to another more durable material. Therefore, it is very rare that they would have been preserved. However, some do survive, such as the collection at the Rodin Museum in Paris. These extant original positive models are so important because they are often the only pieces produced that were made directly by the artist’s hands. They often still have the artist’s fingerprints and can give clues into the artist’s creative process. After being modeled, these models were often taken by others to be transferred into plaster, stone, metal, etc., with some possible final intervention of the artist. In these instances, one can note the changes from these original models to the final sculpture. Even rarer, some works only exist as these original positive models.

This paper will affirm that there are three (3) different modeling pastes with similar characteristics but different formulations that were invented during the period of 1879 and 1897. These new modeling pastes were dry to the touch, permanently malleable, and resistant to heat. It is known that artists like August Rodin, Edgar Degas, and Ismael Smith had used these new formulated modern modeling materials to produce their original models.

The goal of this research was to better understand the origins of these modeling pastes and their chemical characteristics which could then be used to positively identify them at various artwork original models. In addition to identifying these materials, the research also involved observing the main issues of the aging material and how they interact with other materials over time, as well as providing tools to fellow conservators in order to help them with the conservation process of these rare artwork models made with early modeling pastes.