soffietta
A tool consisting of a metal tube, often swan necked, attached to a conical nozzle. The nozzle is used to block the mouth of a glass vessel so that it can be further inflated by blowing into the tube.
soffietta: the glassblower's inflation tube and seal
A soffietta is a metal tube fitted with a conical nozzle designed to seat firmly inside the opening of a partially formed glass vessel. The nozzle blocks the mouth while the tube allows the glassblower to direct compressed air or breath into the interior, inflating the piece further. The tool is typically made from iron or steel, with the tube length ranging from 12 to 20 inches depending on the vessel size and the glassblower's reach requirements.
The characteristic swan neck or goose neck bend in many soffiette serves a practical purpose: it positions the straight nozzle section vertically downward into the vessel opening while keeping the blower's mouth and hands clear of the hot glass and furnace. The conical nozzle tapers to fit snugly; a poor fit will allow air to escape around the seal, defeating the purpose. The nozzle diameter varies, typically from half an inch to two inches, matched to the specific vessel being worked.
Function in the glassblowing sequence
A soffietta enters the process after initial gathering and shaping. Once the glassblower has formed the basic outline using a blowpipe, they transfer the work to a punty for further refinement. At this stage, a soffietta allows controlled inflation without the glassblower's own lung capacity or the larger pressure of compressed air lines. This intermediate tool gives precision for delicate expansions, particularly in thin-walled vessels or when final dimensions require careful control. Removal of the soffietta leaves a small mouth opening that may then be finished, reheated, or further shaped.
The nozzle must be kept clean and relatively cool to prevent sticking to the glass; if the nozzle rim becomes encrusted with cooled glass, the seal fails and must be cleaned at the glory hole before reuse. Overheating the soffietta itself can cause expansion that breaks the seal or damages the conical fit.
The term soffietta comes from Italian, related to soffiare, meaning to blow. It remains standard vocabulary in European glassblowing traditions, particularly in Venetian and Bohemian practices, though English-speaking glassblowers may also call it a blow tube, inflation tube, or simply by the size descriptor of its nozzle.