From Sketch to Hallmark: The Main Stages of a Piece
Written by: L'atelier NAGOYA
A piece of fine jewelry passes through many hands before it reaches its box. From the first drawing to the hallmark, here are the main stages of how it is made.
1. Drawing
Everything begins with a sketch. The designer draws the shapes and volumes and places the stones. The drawing may stay in pencil or be colored in gouache, which renders the shine of the metal and the sparkle of the stones. Anyone can already see the piece to come.
2. 3D modeling
From the drawing, the piece is modeled in three dimensions, at its actual size. It can be viewed from every angle, a thickness can be adjusted, the hold of a stone checked, and the technical files needed for the next steps produced.
3. The model
The piece then takes shape as a model. It can be carved by hand in wax or 3D-printed, which allows very fine detail. This model will be used to make the mold.
4. Lost-wax casting
The model is surrounded with refractory plaster. Heated in a kiln, the plaster cylinder hardens and the wax melts away, leaving its imprint. The caster pours molten gold into it, which takes the place of the wax. Once cooled, the plaster is broken: the piece appears, in raw metal.
5. Bench work
Straight from the casting, the metal is still rough. The jeweler scrapes and files the piece to remove defects, fits the parts together and joins them by soldering, with a flame. It is precision work: the parts must fit without any play.
6. Setting
The stone setter secures the stones on the setting, according to the design and the shape of the gems: bezel, prong, bead or channel setting… This is the step that shows the stones at their best.
7. Polishing
The polisher removes the last tool marks, inside and out, and brings back the shine of the metal. An ultrasonic bath removes the last polishing residue.
8. The hallmark
In France, pieces in gold, silver and platinum bear a fineness hallmark, which guarantees the precious metal content, and a maker’s mark, which identifies the manufacturer. For 18k gold (750), the fineness hallmark is an eagle’s head; for sterling silver (925), the head of Minerva. Gold pieces weighing less than 3 grams are exempt from the guarantee hallmark but must bear the maker’s mark (French customs).
Some stages vary from piece to piece: the gallery of the Gentiane ring, for example, is cut with a saw and adjusted with a file before being soldered, then set by hand in our Saumur workshop. These stages also shape a bespoke project: we describe them in Bespoke Jewelry: How a Project Unfolds in Our Workshop.
Would you rather talk it over in person? We welcome you by appointment at our workshop, 44 rue de Rouen in Saumur, France, or you can write to us from our contact page.
