Bulgari, timeless Tubogas jewels — Patine Gallery Paris

Tubogas refers to a metal technique created in the second half of the 19th century and patented in 1881. This flexible metal pipe with polished contour produced without soldering was sometimes dubbed "skeleton key", "spirotube" or "gas pipe" due to its similarity with tubes made of articulated bands used to transport gas in the 1920s. It was especially popular among several jewelry makers in the 40s at a time where gold was becoming the preferred metal in the industry and pieces with massive volumes were sought after. The making of Tubogas pieces require hours of work by experienced craftsmen who wrap two long gold stripes interlocked onto another in their edges around a core of wood or copper which is then removed directly or dissolved in acid.

Bulgari
18K yellow gold lady's quartz wristwatch with an 18K yellow and white gold integrated Bulgari Tubogas extensible bangle bracelet.
Circa 2000's
© Cambi Casa d'Aste

One of the key features of this design is its flexibility which is especially convenient to create spectacular bracelets or necklaces rolling up perfectly to the neck or wrist of its wearer while, although being quite heavy, remaining very comfortable. The piling up of three or four coils makes the use of Tubogas all the more impressive especially when the pieces are sublimed by precious stones or ancient coins.

Bulgari
Detail of a pair of "Tubogas" earrings in 18K gold and steel
© Bukowskis

From the 1970s Bulgari resorted to this technique to create various pieces such as bracelets, rings, watches to the point that the Tubogas design became one of the symbol of the brand. It is particularly suited to create polychromic pieces with the combination of white, pink and yellow gold strips. The malleability of gold is also well suited to this technique the more so as, unlike other precious metals, its warm hue makes any extremely important piece of jewelry and especially those with large gems more wearable “casually”.

Bulgari
Three Steel, Gold and Gem-Set 'Tubogas' Cuff-Bracelets
Circa 1985
© Sotheby’s

But steel, especially popular in the 1970s when associated with gold, has been the most difficult metal to work with when it comes to the Tubogas technique. Indeed, its high melting point (1300-1500°c) combined with its low ductility makes it all the more difficult to work with, meaning that eventually a Tubogas piece made of steel requires much more hours of work than one made of solid 18k gold.

The Bulgari Tubogas line has given birth to extraordinary pieces combining different elements including ancient coins combined with the modernist and flexible structure of the bracelets.

Bulgari
Gold and ancient coin Tubogas Necklace
18k gold (Italian marks), ancient coin depicting Emperor Maxentius, inscribed on reverse 'Massenzio 306-312 Follis', 13 ins.
© Christie’s

However this technique suits aesthetically the best with one of the emblematic figures of the Bulgari house symbolizing eternity and knowledge : the snake. Indeed, from the 1940s Bulgari created watches with bracelets imitating the snake body thanks to Tubogas and although they are inspired from the past, the cultural Heritage of Bulgari have become timeless ornaments.