Applied Broken Threads

This technique was used in the Renaissance, especially in Catalan glassworks in the façon de Venise of the 16th century, but it also appears in some ribbed cups from the Roman era.

A glass filament is applied to a blown ribbed object which has been significantly cooled.

By rotating the blow pipe which holds the object, it expands slightly and the threads break.

In Renaissance pieces, the ribs were obtained by the 'meza stampaura' technique; other techniques are also now used, for example Lino Tagliapietra from Murano uses the vertically-applied rod technique.