Yetholm-type shield of dots. The artist could not hope to show the fine detail of a Yetholm-type shield, but the similarity is striking. The impressive shields would have indicated high social status. The shields are made of a copper alloy sheet about 0.6 mm thick. The alloy is a high-tin bronze: copper with 11-14% tin. They are round with a central domed boss created by hammering out from the back. The shield face is covered in raised ridges in concentric rings, each a couple of millimetres high. Between the ridges are rings of small hemispherical bosses about 4 mm across. Decoration was
Antimicrobial copper-alloy touch surfaces antimicrobial efficiency tests include: The registrations are based on studies supervised by EPA which found that copper alloys kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly (i.e., the metals are free of dirt or grime that may impede the bacteria's contact with the copper surface). To attain the EPA registrations, the copper alloy groups had to demonstrate strong antimicrobial efficacies according to all of the following rigorous tests: The alloy groups tested and approved were C11000, C51000, C70600, C26000, C75200, and C28000. The EPA registration numbers for the six groups of alloys are as