Hammer was head of one of Norway’s largest silversmithies. He was best known for his plique-a-jour enamelled spoons popular with tourists and exported in large quantities. He produced the ‘Norwegian brilliant enamel work’ spoons offered in the 1896 and 1898 Christmas catalogues of Liberty, London.
He began working with goldsmith Oluf Tostrup, the son of goldsmith Jacob Tostrup and co-owner of J. Tostrup. When Oluf Tostrup died in 1882, Prytz became formally associated with J. Tostrup. He was advanced from head designer to co-owner in 1884, after two years of study. Prytz purchased the entire company after Jacob Tostrup died in 1890, keeping the tradename.
He was born in Gravellona Lomellina, Italy. He was the son of Pehr Ambjörn Sparre af Söfdeborg (1828–1921) and Teresita Adèle Josefa Gaetana Barbavara (1844–1867). His father had served as head of the banknote printing company for the Sveriges Riksbank. He spent his early childhood with his mother at Villa Teresita in Gravellona while his father was often on business trips.
Frederik Lunning, a Danish-born businessman and owner of the Georg Jensen Inc. store on Fifth Avenue in New York, created the Lunning Prize award in December 1951. This successful showcase for Danish porcelain and glass was developed in 1924, but supplies were cut off when World War II broke out.
Riihimäki Glass was a Finnish glass factory. The factory, established in 1810 for the production of domestic glassware, began production of window glass in 1919. It purchased various small factories, including the factory in which the Finnish Glass Museum is located today. After buying the Kaukalahti glassworks in 1927, Riihimaki became the largest glass factory in Finland.