Roman numerals are the signature of this Tissot Chemin des Tourelles, and they transform the character of the watch. Faceted and applied on a blue sunray dial, they give the 39mm T139.807.11.048.00 a traditional, almost ceremonial elegance that sets it apart from the index-dial versions in the collection.

The blue shifts beautifully with the light, from deep navy at a desk to bright royal blue outdoors, and the polished steel case and bracelet frame it cleanly. A gently domed sapphire crystal gives the profile a soft curve, while the date sits discreetly at six o’clock.

Inside is Tissot’s Powermatic 80, a Swiss automatic movement with a Nivachron balance spring and around 80 hours of reserve, so it keeps running through a weekend in the watch box. The 39mm case is 11.2mm thick with 20mm lugs, and the steel bracelet is interchangeable without tools. The collection’s name recalls the Le Locle street where Tissot opened its factory in 1907.

Tissot T139.807.11.048.00: blue dial with Roman numerals

• Diameter 39mm, thickness 11.2mm, lug width 20mm
• 316L stainless steel case, polished and brushed
• Blue sunray dial with faceted Roman numerals and date
• Powermatic 80.111 automatic with Nivachron hairspring
• Approximately 80 hours of power reserve
• Domed sapphire crystal; transparent caseback
• Water resistant to 50 meters
• Interchangeable steel bracelet, push-button butterfly clasp

Formal enough for black tie, relaxed enough for Friday, the Roman-numeral blue Chemin des Tourelles is a watch with real old-school charm.