Glossary · Materials
Chromexcel - Horween Leather - Milano Straps
Definition
Chromexcel is Horween's flagship leather – a vegetable-mineral tanned bovine hide from the historic Chicago tannery founded in 1905. What fascinates me about this leather, and what I recommend to our clients, is its defining characteristic: robustness paired with immediate softness. It lacks the initial stiffness of other Horween leathers like Chrometan. Chromexcel develops a rich, stratified patina naturally over time, generating beautiful honey and sand-colored striations as it ages. Perfect for watch straps, especially on vintage sports chronographs and tools like the Rolex Daytona ref. or Omega Seamaster. The tanning process combines chrome and vegetable tannins, making it water-resistant and resilient to atmospheric conditions while maintaining a natural feel. For those seeking a strap that tells a story – that of time passing – Chromexcel is the conscious choice.
Frequently asked questions
Is Chromexcel suitable for a Rolex Daytona or should I prefer Horween Shell Cordovan?
It depends on usage. Chromexcel on a vintage Daytona (ref. 6239 or 6262) is literally historical: in the 1960s-70s, Rolex used Horween leather for many pilot and sports straps. The advantage? Natural patina, scratch resistance, softness. However, if you're seeking a formal look on a modern Daytona, Shell Cordovan offers that almost glossy elegance. I prefer Chromexcel for character watches – those that truly live on your wrist.
How does Chromexcel age? Does it require special maintenance?
It ages magnificently. In the first months, you'll notice a color shift toward honey and sand tones; after 2-3 years, the patina becomes truly deep. It doesn't require complex maintenance. Once a month, a soft damp cloth to remove dust; every 3-4 months, a light application of vegetable conditioner (no silicones). Avoid standing water – Chromexcel is water-resistant, not waterproof. On an IWC Pilot strap at 20mm, you'll see this evolution with particular clarity thanks to the narrow width and movement visibility.
What size Chromexcel for a Patek Philippe Aquanaut or Omega Seamaster?
The Aquanaut sits well at 22mm, sometimes 20mm for more compact models. On the Omega Seamaster, it depends on the caliber: modern Planet Ocean models are ideally 22mm, while vintage Professional 300m watches often came with 20mm. Chromexcel in both cases delivers extraordinary authenticity, especially on vintage 1970s-80s Seamaster models. The extra width of 22mm in Chromexcel leather offers a tactile solidity that synthetic straps will never match. I recommend it, especially if your watch will be a real tool and not just a display piece.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only