The term filigree, in the goldsmith's art, mainly indicates the artistic technique which consists in interweaving thin gold and/or silver threads which, after twisting, are fixed on a support also of noble material to create an elegant openwork effect. The decorative patterns are created by bending and soldering thin gold or silver wires, which are soldered together at the contact points.

Granulation is a decorative goldsmith technique which until now has had no structural function to create a jewel. It uses gold microspheres to decorate jewels according to personal aesthetic tastes.

The central point of this decorative technique is the method of welding the granules to the underlying surface; in short, it consists in exploiting the properties of the generically called "copper salts".

In the middle of the last century, fragments of a destroyed ring belonging to the legendary goldsmith artist Galdino Saba appeared in the capital of Sardinia, Cagliari. Nobody knew the origin and the past of this jewel. The fineness of the watermark, the tiny granulation, indicated a historic work of art by a great old master, but no one wanted to bother with an elaborate reproduction.