Information taken from Scandinavian Silver Co….
Guilloche enamel butterfly by the leading Norwegian silversmith, David-Andersen. This design has been one of the company’s most popular, and the butterfly has been produced in a myriad of colours and several multicolours, as well as 3 sizes. It has been widely exported, and there are probably more flying around in the United States than in Norway. The butterfly is made of sterling silver and treated with a gold wash (vermeil). It is then guilloched (given the pattern seen through the enamel) and finally coated with a coloured transparent enamel. This mid- blue example is the medium size.
Note *Guilloché (Guilloche) is a decorative engraving technique in which a very precise intricate repetitive pattern or design is mechanically engraved into an underlying material with fine detail. Specifically, it involves a technique of engine turning, called guilloché in French after the French engineer “Guillot”, who invented a machine “that could scratch fine patterns and designs on metallic surfaces”. The machine, called a rose engine, improved upon the more time-consuming practice of making similar designs by hand, allowing for greater delicacy, precision, and closeness of the line, as well as greater speed.
Note to self … bid OnlineAuction.com l seller Letsplaytagsales… love this blue one!!