Cartier Ballon Bleu 42mm · Ref. CARTIER BALLON BLEU 42 · 20mm lug · 42.1mm case
At a Glance
| # | Best For | Strap | Material | Thickness |
|---|---|---|---|---|
| 1 | Overall / First Purchase | Taupe Epsom Slim Strap | Epsom Calfskin | 2.2mm |
| 2 | Dressy / Formal | Glossy Lagoon Blue Crocodile Signature Strap | Crocodile | 4.5–2.2mm |
| 3 | Everyday / Casual | Sand Nubuck Slim Strap | Nubuck Calfskin | 2.2mm |
| 4 | Minimalist / Refined | Natural Shell Cordovan Slim Strap | Shell Cordovan | 2.2mm |
| 5 | Casual / Relaxed | Green Crazy Horse Side-Stitch Strap | Waxy Leather | 2.5mm |
| 6 | Active / Sporty | White Tropical CTS Rubber Strap | FKM Rubber (Tropical) | 4.0–3.3mm |
| 7 | Comfort / Wildcard | Warm Grey Hook Strap [kollokium x Delugs] | Fabric | 1.3mm |
Cartier's watches are not trying to be like Swiss tool watches — they are doing their own thing, and that confidence is magnetic. The Ballon Bleu 42mm (ref. CARTIER BALLON BLEU 42) is a case in point. The finishing and attention to detail speak for themselves. A 20mm lug width and that unmistakable character make this watch a natural platform for strap changes.
The 42.1mm case with its 13mm profile gives you just enough wrist presence to anchor different strap materials without the watch disappearing. Here are my 7 picks — and why each one works.
Quick Specs
| Case diameter | 42.1mm |
| Lug width | 20mm |
| Lug-to-lug | ~49mm |
| Case thickness | 13mm |
| Water resistance | 30m |
| Crystal | Sapphire |
| Case material | |
| Movement | Calibre 1847 MC (automatic, ~42hr power reserve) |
The 20mm lug width means your options are curated but well-covered. Already know what you're looking for? Browse all Cartier Ballon Bleu 42mm-compatible straps on the Strap Finder →
1. Best Overall — Taupe Epsom Slim Strap
There's a reason this is the number one pick — it just works.
The Taupe Epsom Slim Strap features Epsom leather, tanned by Haas. The fine, uniform grain gives it a clean, contemporary look that resists scratches and moisture with ease. This is leather that looks as sharp six months from now as it does on day one. At 2.2mm thick, it balances presence and wearability nicely.
What makes this pairing work on the Cartier Ballon Bleu 42mm is the contrast — the refined case finishing against the texture creates visual interest without conflict. With a 42.1mm case, the proportions stay balanced.
A combination that's greater than the sum of its parts.
Worth a look in other colourways:
- Black Epsom Slim Strap
- Tinware Grey Epsom Slim Strap
- Hunter Green Epsom Slim Strap
- Izmir Blue Epsom Slim Strap
2. Best Dressy — Glossy Lagoon Blue Crocodile Signature Strap
Formal occasions call for something elevated. This delivers without being flashy.
The Glossy Lagoon Blue Crocodile Signature Strap is made from genuine crocodile leather with a distinctive scale pattern that no embossed leather can replicate. The texture adds visual depth and character that works equally well with a suit or a smart-casual outfit. At 4.5–2.2mm thick, it balances presence and wearability nicely.
Paired with the Cartier Ballon Bleu 42mm's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The 13mm case thickness means a padded strap like this one feels proportional and substantial.
The kind of strap that earns a permanent spot in your rotation.
If this style appeals but you want a different tone:
- Glossy Caramel Crocodile Signature Strap
- Glossy Emerald Crocodile Signature Strap
- Glossy Taupe Brown Crocodile Signature Strap
- Glossy Grey Crocodile Signature Strap
3. Best Everyday — Sand Nubuck Slim Strap
For daily wear, comfort and versatility matter more than anything else.
The Sand Nubuck Slim Strap is crafted from nubuck leather — soft, velvety to the touch, and comfortable from the first wear. No break-in period needed. The suede-like texture adds a casual warmth that takes the edge off a formal watch without losing sophistication. At 2.2mm thick, it balances presence and wearability nicely.
Paired with the Cartier Ballon Bleu 42mm's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The 13mm case thickness means a padded strap like this one feels proportional and substantial.
It's the kind of pairing that makes you wonder why you didn't try it sooner.
Other colours worth considering:
- Natural Nubuck Slim Strap
- Navy Nubuck Slim Strap
- Light Grey Nubuck Slim Strap
- Dark Brown Nubuck Slim Strap
4. Best Minimalist — Natural Shell Cordovan Slim Strap
Minimalism isn't about doing less. It's about doing exactly what's needed.
The Natural Shell Cordovan Slim Strap is crafted from premium materials with careful attention to detail and construction quality. At 2.2mm thick, it balances presence and wearability nicely.
Paired with the Cartier Ballon Bleu 42mm's distinctive dial, this strap adds a layer of personality that the factory option does not offer. The 13mm case thickness means a padded strap like this one feels proportional and substantial.
It's the kind of pairing that makes you wonder why you didn't try it sooner.
Other colours worth considering:
- Black Shell Cordovan Slim Strap
- Navy Shell Cordovan Slim Strap
- Cognac Shell Cordovan Slim Strap
- Green Shell Cordovan Slim Strap
5. Best Casual — Green Crazy Horse Side-Stitch Strap
Weekend straps should feel effortless. This one nails that.
The Green Crazy Horse Side-Stitch Strap uses crazy horse leather — an oil-infused leather that develops character with every scratch and mark. Rub a scratch with your thumb and it blends right back in. It is built for people who actually wear their watches, not baby them. At 2.5mm thick, it balances presence and wearability nicely.
The Cartier Ballon Bleu 42mm's 42.1mm case is ideally proportioned for this strap. Whether you are wearing it casually or dressing it up, the combination feels intentional. It is the kind of pairing where both the watch and strap look better together than apart.
The range goes deeper if you want to explore:
- Black Crazy Horse Side-Stitch Strap
- Mocha Crazy Horse Side-Stitch Strap
- Tan Crazy Horse Side-Stitch Strap
- Cognac Crazy Horse Side-Stitch Strap
6. Best Sporty — White Tropical CTS Rubber Strap
When you want your Cartier Ballon Bleu 42mm to feel more relaxed and sporty, this is the pick.
The White Tropical CTS Rubber Strap is made from FKM rubber — a high-performance elastomer that resists chemicals, heat, and ageing. Unlike silicone, it does not attract dust or lint. Cut-to-size construction means you trim it to your exact wrist measurement — no leftover tail, no keepers. At 4.0–3.3mm thick, it balances presence and wearability nicely.
On the Cartier Ballon Bleu 42mm, this strap preserves the watch's go-anywhere character. The 42.1mm case at 13mm thick pairs naturally with the padded construction without creating any imbalance on the wrist.
Once you see it on the wrist, it just clicks.
The range goes deeper if you want to explore:
7. The Wildcard — Warm Grey Hook Strap [kollokium x Delugs]
![Warm Grey Hook Strap [kollokium x Delugs] on Cartier Ballon Bleu 42mm](https://cdn.shopify.com/s/files/1/0054/9040/9585/files/20250919-A7405207.jpg?v=1761299094&width=800)
This one's different — and that's exactly the point.
The Warm Grey Hook Strap [kollokium x Delugs] is crafted from premium materials with careful attention to detail and construction quality. At 1.3mm thick, it balances presence and wearability nicely.
![Warm Grey Hook Strap [kollokium x Delugs]](https://cdn.shopify.com/s/files/1/0054/9040/9585/files/Kollokium_straps_Warm_Grey_1.jpg?v=1761299094)
On the Cartier Ballon Bleu 42mm, this strap preserves the watch's go-anywhere character. The 42.1mm case at 13mm thick pairs naturally with the padded construction without creating any imbalance on the wrist.
It's the kind of pairing that makes you wonder why you didn't try it sooner.
Other colours worth considering:
- Anthracite Hook Strap [kollokium x Delugs]
- Black Hook Strap [kollokium x Delugs]
- Khaki-Green Hook Strap [kollokium x Delugs]
- Orange Hook Strap [kollokium x Delugs]
A Note on Buckle Colour
Quick but important: always match your buckle to your case. The Cartier Ballon Bleu 42mm's case calls for a silver (brushed or polished) buckle. All Delugs leather straps ship with a pin buckle and can be upgraded to a Spring Deployant Clasp for extra security and convenience. All Delugs straps come with quick-release spring bars pre-installed, so swapping straps takes seconds.
How to Change the Strap on Your Cartier Ballon Bleu 42mm
Swapping straps on the Cartier Ballon Bleu 42mm is one of the easiest upgrades you can make — and with Delugs straps, you don't even need a tool.
If your Cartier Ballon Bleu 42mm came on a bracelet, you'll first need to remove it. The easiest way to do this at home is with a Bracelet Removal Tool, which lets you compress the spring bars without risking scratches to the lugs or caseback. Once the bracelet is off, you can slide your new Delugs strap straight in.
All Delugs straps come with quick-release spring bars already pre-installed, so changing straps is completely tool-free. Here's how:
- Prepare your workspace. Lay the watch face-down on a soft cloth or microfiber pad to protect the caseback from scratches.
- Release the spring bar. Locate the small lever on the quick-release spring bar. Pull it back with your fingernail or fingertip to compress the bar.
- Remove the strap. While holding the lever, angle the strap out from between the lugs. Repeat for the other side.
- Insert the new strap. Slide one end of the spring bar into the lug hole. Pull the lever on the quick-release spring bar knob, guide the entire spring bar into the opposite lug hole, and then release the knob. You should hear a small click when the spring bar extends and seats into the lug hole.
- Check the fit. Give the strap a gentle tug to make sure both spring bars are securely locked in. If there's any play, reseat the spring bar.
The entire process takes under a minute once you get the hang of it — no spring bar tool required. The Cartier Ballon Bleu 42mm uses a standard 20mm lug width, and all Delugs straps in 20mm will fit perfectly.
Frequently Asked Questions
What is the lug width of the Cartier CARTIER BALLON BLEU 42?
The Cartier CARTIER BALLON BLEU 42 has a 20mm lug width. While 20mm is less common than 20mm, there is still a strong selection of quality straps available. All Delugs straps are available in 20mm.
What is the reference number for the Cartier Ballon Bleu 42mm?
The reference number for the Cartier Ballon Bleu 42mm is CARTIER BALLON BLEU 42. You can find this on the caseback of your watch or on the original paperwork. Knowing your reference number helps ensure you get the right lug width when ordering a strap.
Can I use a dressy leather strap on a Cartier versatile watch?
The Ballon Bleu 42mm is one of the most versatile watches in the Cartier lineup — it takes both dressy and casual straps equally well. That's part of what makes it such a rewarding watch for strap changes. Don't be afraid to experiment.
Do Delugs straps come with spring bars?
Yes — every Delugs strap comes with quick-release spring bars pre-installed. This means you can change straps by hand in seconds, without needing any tools. The quick-release mechanism uses a small lever that you pull with your fingertip to compress the spring bar.
What is the best strap material for the Cartier Ballon Bleu 42mm?
The Ballon Bleu 42mm's versatile nature means it works with almost everything. Start with what matches your most common wearing occasion — rubber or sailcloth for active use, nubuck or waxy leather for everyday, and alligator or saffiano for dressier moments. The Strap Finder makes it easy to browse by material and style.
Does Cartier use quick-release spring bars?
Most Cartier watches use standard spring bars that require a tool to remove. All Delugs straps come with quick-release spring bars pre-installed, so once you make the switch, future changes are completely tool-free.
Where can I find straps compatible with the Cartier CARTIER BALLON BLEU 42?
The Cartier Strap Finder shows every Delugs strap compatible with the CARTIER BALLON BLEU 42, filtered by lug width and style. You can also use the general Strap Finder to browse by brand, collection, and material. If you need help choosing, our team is available 24/7 via live chat.
Finding Your Strap
The beauty of the Cartier Ballon Bleu 42mm is that it rewards experimentation. A dressy alligator for the office, nubuck for the weekend — each strap brings out a different side of the watch.
Use the Cartier Ballon Bleu 42mm Strap Finder to see every compatible strap in one place, filtered to your exact reference. Or if you'd rather explore by feel, the general Cartier Strap Finder lets you browse the full lineup and find your match.
Not sure which strap is right for your specific Ballon Bleu 42mm? Our team is available 24/7 via live chat — drop us a message and we'll help you find the perfect match for your watch, wrist size, and style.
About Delugs
Founded in 2018 and headquartered in Singapore, Delugs is dedicated to elevating the experience of watch ownership through the simple yet powerful act of strap changing. We believe that straps are integral to how a timepiece is worn, perceived, and enjoyed. Our mission is to make strap changing a lifestyle — an everyday act of self-expression and versatility.
Delugs is an independent brand with a global community of clients, with a strong online presence and growing physical retail footprint. Our direct-to-consumer focus keeps us closely connected with the watch enthusiast community — fostering conversations, hosting events, and helping shape a more inclusive and expressive culture around watch collecting. We also work closely with watch brands to craft straps that complement their timepieces, bridging the gap between brand and collector, form and function.
Our catalogue spans leather, rubber, and fabric straps, with options for every watch and every occasion. We are committed to craftsmanship and quality, product design and innovation, and outstanding customer service. We offer watch owners the freedom to change straps as easily as changing outfits, and the opportunity to engage more deeply with the watches they love.
Visit our flagship boutique at Raffles Hotel, Singapore →
— Marcus
![Anthracite Hook Strap [kollokium x Delugs] - Image 2](http://delugs.com/cdn/shop/files/20250919-A7405309_298x298_crop_center.jpg?v=1761299094)
![Delugs Anthracite Hook Strap [kollokium x Delugs] Fabric Watch Strap](http://delugs.com/cdn/shop/files/Kollokium_straps_Anthracite_1_298x298_crop_center.jpg?v=1761299094)
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