Fine glass paperweights, first produced in France in 1845, are now widely appreciated as works of art. They are made entirely of glass by sole artisans, or factories, usually in limited editions. Millefiori (Italian-thousand flowers) paperweights contain thin cross-sections of cylindrical composite canes made from colored rods and usually resemble little flowers. They exist in many variations such as scattered, patterned, close concentric or carpet ground. Lampwork paperweights have objects such as flowers, fruit, butterflies or animals constructed by shaping and working bits of colored glass with a gas burner or torch and assembling them into attractive compositions, which are then incorporated into the dome.
Visible flaws, such as bubbles, striations and scratches affect the value. Glass should not have a yellow or greenish cast, and there should be no unintentional asymmetries, or unevenly spaced or broken elements. Generally, larger weights are more costly and desirable. In a modern piece, an identifying mark and date are imperative. Workmanship, design, rarity, and condition determine its value.