Reportedly Trivulzio collection, Milan; (Count Alessandro Contini-Bonacossi, Florence); purchased by 1937 or 1939 by Samuel H. Kress, New York, as Sienese, c. 1500; gift 27 February 1950 to the Samuel H. Kress Foundation, New York; gift 1961 to NGA.
- Distelberger, Rudolf, Alison Luchs, Philippe Verdier, and Timonthy H. Wilson. Western Decorative Arts, Part I: Medieval, Renaissance, and Historicizing Styles including Metalwork, Enamels, and Ceramics. The Collections of the National Gallery of Art Systematic Catalogue. Washington, 1993: 45-48, fig. 46.
The ornaments are attached to a pieced strip of worn, dark red velvet with a satin backing, of uncertain date. Eight are enameled in blue.
X-ray fluorescence analysis of the metal disks indicated they are made of mercury-gilded (fire-gilded) silver. The light and dark blue enameled areas contain silver (perhaps from the base) and small amounts of copper, zinc, and lead. The green areas contain the same elements, with a greater concentration of copper, which is probably responsible for the coloration in both the blue and green areas.
 Report, 19 March 1987, in NGA conservation laboratory files.