Glossary · Materials
City Calf
Definition
City Calf is a full-grain calf leather of the highest quality, a historic trademark of Prada tannery. It is a smooth, dense, and compact leather subjected to vegetable tanning that enhances its resistance to daily wear. At Milano Straps we use it for watch straps because it offers a natural silky finish, controlled thickness (approximately 1.4–1.6mm), and that dark patina that does not darken further over time—perfect for those who dislike chromatic surprises. It is gentleman's leather: sober, professional, indestructible. The natural grain remains always visible even after years of use. For those wearing a Rolex Datejust or a Patek Philippe Aquanaut, City Calf represents the balance between tactile luxury and practical longevity. It requires no frequent conditioning, and ages with dignity.
Frequently asked questions
Is City Calf suitable for watch straps only for dress or also sports watches?
Both. City Calf is versatile because, despite its inherent elegance, it has surprising robustness. On a Submariner 40mm or an IWC Pilot in steel version, a City Calf strap brings seriousness without overdoing it. Technically, the leather's density allows reduced thicknesses (perfect for 20–22mm) without sacrificing durability. The only constraint: it is not leather for frequent immersions—for that, I recommend alligator or rubber.
How does City Calf age? Does it develop creases or change color?
No visible creasing—City Calf is too dense for that. Change color? Minimally. Prada tannery's vegetable tanning stabilizes the tannin, so the leather maintains its dark profile with imperceptible variations over time. You will see natural polishing due to friction (wrist, cage friction), but nothing dramatic. This is the advantage of serious leather: it is not a chromatic chameleon like Barenia or traditional Box Calf.
Which classic watch do you recommend City Calf for?
Patek Philippe Aquanaut (any diameter), Rolex Datejust 36–41mm, Omega Seamaster Diver in dress version (yes, it exists). If you love IWCs, the Portofino 40mm with City Calf is a sober and intelligent combination. Ideal sizes: 18mm for vintage Datejust 36, 20mm for Aquanaut, 22mm for Seamaster 42. City Calf does not compete with rubber or metal on aggressive wrist chronographs; it shines where leather must whisper competence.
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