Mosaic glass vessels captivated late-nineteenth-century collectors, who especially sought ancient examples. Intact antique cups and bowls were rare, and even fragments were eagerly purchased. At some point prior to its donation to the Smithsonian Institution in 1929, this blue bowl was reconstructed using surviving shards and plaster to fill the gaps. Following turn-of-the-century restoration practices, these insertions were painted with rough approximations of the overall patterns. Strong lights reveal which sections are glass (dark but transparent) and which are plaster (completely opaque).