There are many small details on Rolex watches that you may not be aware at first glance. The company consistently improves and refines its products, making small tweaks of visual details, materials used, and technical improvements. All of this to improve their durability, reliability, and overall performance.
If you found out that a Rolex watch and found the text ”T SWISS T” or ”Swiss-T <25”, or perhaps ”Swiss”, printed at the bottom of the dial at 6 o’clock, what does it represent ?
The fact is that the different Swiss printings on the Rolex dials actually indicate something, and are not just there for decoration.
Rolex has used a number of different Swiss made printings on its dials over the years. The dial printing actually relates to the luminous material used for the indices and hands.
In its early days, Rolex used radium paint for the luminosity of its watches. These early Rolex watches have ”SWISS” printed at the bottom of the dial at 6 o’clock. The catch is that Rolex would also later come to use the same printing again (more on that later). Radium is an extremely radioactive substance and due to health concerns, and the introduction of new luminous materials over time, Rolex eventually replaced the radium paint.
Later on, Rolex replaced the radium with tritium, and the above markings were used on the radium watches to indicate such. The benefit of tritium is not as radioactive as the Radium. However, the downside of tritium has a half-life of 12 years, which means that over the years, it will lose its glow.
Rolex used tritium up until the 1990s when it replaced it with yet another material. Rolex changed to luminova in around 1999. Rolex used lumina for a relatively short period of time, and this can be seen with the watches that have ”Swiss” printed on the dial. These watches are referred to by collectors as ”Swiss only” dial, as they only feature the Swiss word.
Later on, Rolex changed to Superluminova, and now, Rolex has ”Swiss made” on all of its watches. However, in recent years, Rolex has started printing the logo coronet between Swiss and Made, to indicate that the watch has a second-generation movement
This printing indicates that the watch uses tritium (T=tritium) and tells us that the tritium emits less than 227 MBq (7.5 mCi). This printing also indicates that the indices are made in gold.