Q: What does the "σSWISSσ" notation mean, as seen on old watches?
A: It is a mark that indicates a model with a gold index.
If you look at luxury watches from the 1970s and 80s, you will often see the inscription "σSWISSσ" underneath the dial. This is called the "Sigma Mark." Some Swiss-made watches used it from 1971 to 95. This mark was only used on Swiss-made dials with gold indices.
However, not all watches that met these criteria bore the Sigma mark: only five manufacturers, Patek Philippe, Rolex, Vacheron Constantin, IWC, and Omega, were allowed to use the mark, all of which belonged to the APRIOR (Association Pour la Promotion Industrielle de l'Or), a group of Swiss suppliers.
Photograph by Masanori Yoshie
The dial doesn't have to be gold.
Although it is often misunderstood, this mark could be used even if the dial itself was not made of gold, as long as the indexes were made of gold.
If you see the Sigma mark on your watch, you can assume that it is a high-quality product with gold indices. However, the use of the Sigma mark was discontinued in 95, and APRIOR itself was dissolved in 2007.
