Delcam’s ArtCAM used in recreating the Cheapside Hoard
The Museum of London, in partnership with the Jewellery Industry Innovation Centre (JIIC) at the Birmingham Institute of Art and Design, is using Delcam’s ArtCAM artistic CADCAM software to investigate the Cheapside Hoard, the greatest hoard of Elizabethan and Jacobean jewellery in the world, to discover more about the methods that could have been used to create the pieces.
Dr. Ann-Marie Carey, a research fellow at JIIC, remembered, "When we received photographs of the Cheapside Hoard, we were fascinated with the level of detail in the jewellery. We started to ask ourselves how such pieces were made and wanted to understand the craftsmanship involved.”
Dr. Carey worked with Hazel Forsyth, the Senior Curator of the Medieval and Post-Medieval Collections at the Museum of London, and Keith Adcock, a Senior CADCAM Technologist at JIIC. The team spent several days at the Museum taking photographs and digital scans of the items for analysis.
Unfortunately, some of the collection had suffered significant deterioration over the years. This meant that, before the team members could determine how some of the pieces were created, they needed to visualise how they would have looked by either partially or completely recreating them. To do this, the team used a range of techniques including using photographs to help recreate objects in CAD, laser-scanning the pieces, or a combination of both.
One of the Cheapside Hoard pieces to suffer considerable corrosion was a gild brass verge watch signed by G. Ferlite. Unlike other items in the collection, this could not be laser-scanned easily. "Laser scanners do not work well with shiny objects such as gem stones, glassware and polished gold,” explained Mr. Adcock. "For us to accurately scan the Ferlite watch, we would have had to chip out the enamel and spray it white, which, obviously, we weren’t going to do. Nonetheless, we scanned the dial of the watch but the results needed CAD interpretation and enhancement.”
The watch face was recreated with ArtCAM JewelSmith. With the Delcam software, Mr. Adcock imported a photograph of the watch face and used ArtCAM’s ‘Relief from Image’ tool to create a model surface. This removed the need to trace around every part of the imported image to create the vector artwork. "ArtCAM is absolutely fabulous for interpreting photographs and creating textures,” claimed Mr. Adcock.
The effects of the corrosion on some areas, such as the day-dial on the right-hand side of the watch face, meant that some of the automatically-generated reliefs needed to be modified. Mr. Adcock used ArtCAM’s advanced vector drawing tools to trace quickly around the parts he wanted to edit. These areas were remodelled in ArtCAM and combined with the reliefs generated from the scan data. Smoothing tools were then used to soften the surface finish before the complete model was rendered in ArtCAM to show the piece as it would have looked prior to receiving its enamel finish.
The next step was to create a physical model of the piece with 3D printing. Support structures were added to the ArtCAM model and the complete design supplied to the printer.