Bonhams remains the only international auction house to have dedicated glass and paperweight sales, continuing with its auction of Fine Paperweights from the collection of the late Baroness de Bellet.
The auction will be held on May 19 in New Bond Street, London.
Collected in America, London and more recently held in Switzerland, the group spans three generations of a family of collectors and promises many beautiful floral and millefiori designs of outstanding beauty and exquisite detail.
The Baroness' grandfather initially assembled the collection in the 1920s when paperweights were not in vogue.
He lived in America and favoured paperweights of mid 19th century French and American design, such as the Boston & Sandwich flower paperweights estimated at �400-500 each.
His son continued to add to the collection, focusing on weights from the French Classic Period (1845-53), especially those from the great factories of Baccarat and Clichy.
Particular highlights up for auction will include the Baccarat Chouffleur carpet-ground example (�5,000-7,000), the unrecorded Baccarat flower (�7,000-9,000), the Clichy stylised flower (�3,500-4,500) and the Clichy bouquet (�6,000-8,000).
Some of the millefiori weights in the collection were created in France at the time of the Revolution of 1848, accounting for the predominance of the red, white and blue colours with manufacturers keen to demonstrate their nationalism.
An example in this sale is a Baccarat close-pack millefiori design dated 1848 which also includes a silhouette of a cockerel - the French national symbol (estimate �1,200-1,800).
The sale also features several rare large Mount Washington paperweights estimated at �10,000 - 15,000 each. The Mount Washington firm flourished in America in the mid-19th century, and these weights are known for their large size - some as big as 11cm in diameter, for example the magnum bouquet with three-dimensional flowers.
There are weights with latticinio work favoured by the manufacturers of St Louis, Baccarat and Clichy, who also created many beautiful floral designs, particularly the dahlia and mixed sprays of pansies and roses.
"This is an outstanding collection of market fresh paperweights celebrating the exquisite and highly detailed work of French and American glassmakers," said Simon Cottle, Departmental Head of Glass and Continental Porcelain at Bonhams.
"Bonhams is honoured to be showcasing such an unusual collection spanning three countries and three generations of collectors."