How do you fully document a large counter relief object such as this early 19th century cake mold featuring General Washington?
The cake mold as photographed under normal conditions in the lab.
RTI, short for Reflectance Transform Imaging, is a technique in which multiple photographs are taken of an object with the light coming from a different direction in each picture. The several photographs are then fed into a special computer program that combines them, reads the surface texture of the object, and creates a composite image with almost 3-dimensional feel.
|31 images were assembled to create this RTI|
The RTI documents all the details of the object for posterity.
Although the technology has been available for a few years it is just beginning to see popular use and has never been used here at Shelburne before. Thanks to the work of the folks at Cultural Heritage Imaging, the RTI tools and technique have become much more easily available to anyone who wants to use this powerful technology. I recently taught myself the technique and assembled the necessary (very basic) equipment, and with the help of conservation intern Rosella Fevola, we successfully created an RTI image of the Washington cake mold on our first attempt.
We intend to keep experimenting with the opportunities and limitations of this technology and find new ways to fit it into our conservation process here at Shelburne.