This group of classic Bohemian/Silesian paperweights are known as “Bussolin” weights. The millefiori canes scattered on a muslin cushion were produced by a Venetian glassmaker called Domenico Bussolin. According to new findings, after he was forced to close his business in Venice in 1842, accompanied by a number of his fellow glassworkers, he travelled to the Riesen-/Isergebirge region - where the majority of Silesian and Bohemian glassworks were located - to sell his canes. Maybe he made new canes while he was there - or even paperweights - but so far, it has not proved possible to identify the glassworks which actually produced the paperweights which contain his canes.
Broad basal rim around a polished central concavity.
(See Chapter 6 in Peter von Brackel's book "Classic Paperweights from Silesia/Bohemia")