Strap for Classique Date Automatic 39mm Guilloche

The Montblanc Star 113823 has a lug width of 19 millimetres. This measurement represents the linear distance between the internal terminals of the case where the strap is seated. It is a critical parameter to ensure complete compatibility and rotational stability during daily wear.

For the Montblanc Star 113823 we recommend straps crafted from natural leather with vegetable tanning (alligator, Cxl calf) for formal contexts, or ballistic nylon NATO straps for daily and sports use. Your choice depends on the desired colour matching and intended use: cognac brown for formal elegance, black for business settings, navy blue for versatile casual wear.

Strap changing requires removal of the replacement lugs from the case. Position the watch on a soft surface (microfiber cloth), then use a spring bar tool—a lever-action implement with a rounded tip—to compress the spring bar pin of the first lug, extracting it gently. Repeat for the opposite lug. Insert the new strap by aligning the slots with the lugs, ensuring the spring bar pins are fully locked.

Yes, any strap designed for a 19mm lug width is compatible with the Star 113823, regardless of manufacturer. However, it is essential to verify the tolerance between the strap slots and case lugs: this must remain within 0.1–0.3 millimetres to guarantee optimal grip and rotational stability. Bespoke quality straps feature tighter tolerances than standard industrial production.

A natural leather strap subjected to vegetable tanning maintains structural integrity for 3–5 years with daily wear, developing a characteristic patina over time. Longevity depends on frequency of use, sun exposure, humidity and preventive care. A vegetable-tanned leather strap ages nobly, whereas a chrome-tanned strap tends to deteriorate more rapidly. Periodic replacement is a natural part of watch maintenance.