Horween Leather: A Watch Nerd’s Primer

Let’s face it, most watch nerds love leather. A leather strap can drastically change the look of a watch, and most of us have more straps than we do watches. In recent years we’ve been treated to a number of options, and not just from the big boys like Hirsch and Di-Modell, but also from small artisans creating beautiful custom straps from all sorts of hides. With all these choices, however, there’s bound to be some confusion, especially when some of these non-OEM straps cost upwards of $200. So a light bulb went off in my head; let’s give our readers a small primer clearing up some of the confusion by taking a look at one of the best leather tanneries in the world, Chicago’s Horween Leather Company, with a focus on two different types of leather that have become increasingly popular in the last couple of years: Chromexcel and shell Cordovan.


Horween: An American Institution

Isadore Horween, a Ukrainian immigrant, founded Horween Leather Company in 1905 on Division Street in Chicago. Though the Horween of today sports an impressive portfolio, the company first focused on making razor strops for sharpening blades. As the times and tastes changed, the company expanded into other areas, producing everything from football leather for the NFL to water-resistant footwear for the U.S. Marine Corps. While most tanneries eventually moved overseas to take advantage of lower labor costs, Horween stayed put (only moving once in 1920 to Chicago’s north side). Today, Horween is still family operated under the tutelage of a 4th generation Horween, Skip, and his son, Nick. They employ approximately 160 unionized workers, many of whom have been with the company for decades and have honed their skills to nearly irreplaceable precision. Most savvy consumers know Horween for their shell cordovan and Chromexcel leathers, used by countless brands in their wares. So what makes these two leathers so special?




Chromexcel is a type of leather specific to Horween, made from a formula developed by the company in 1911 that to this day remains largely unchanged. In order to appreciate Chromexcel, it’s important to first understand the two different methods of tanning leather: chrome tanning and vegetable tanning.

Chrome tanning, also known as mineral tanning, is a relatively modern process, although the majority of the world’s leather today is chrome tanned. The method is arguably simple, and involves hides soaked and tumbled in drums containing a solution of chromium sulfates, acids, and salts that stabilize the leather. The benefit of chrome tanning, and why it’s the preferred choice for many manufacturers, is that it’s quick; the entire process usually takes one day. The resulting leather is also soft from the get-go, more consistent in and receptive to color, and has excellent water resistance. The downside, however, is that chrome tanned leather often smells of chemicals and can look somewhat synthetic, and ultimately doesn’t wear too well.

Wolverine 1000 Mile Boots in Black Chromexcel

Vegetable tanning is the much older brother of the two methods. It’s a natural process, using tannins extracted from a number of different tree barks, including pine, birch, mimosa, mangrove, etc. It is also far more artisanal than chrome tanning, and can take up to 60 days to do properly. The resulting hide boasts deep, rich tones and has a capacity to develop a beautiful patina over time. If you own a leather item that looks better now than when you first bought it, it’s likely vegetable tanned. The only major downside to vegetable tanned leather is that it is more susceptible to water and heat.

Though I personally prefer my leather of the vegetable tanned variety, both methods have their uses. While I’d rather own a pair of vegetable tanned dress shoes, a pair of chrome tanned hiking boots make more sense due to their practicality against the elements. Regardless of the method used, both processes can result in a quality product as long as no short cuts are taken. Even the “best” method in the wrong hands can yield substandard results.

Alden Indy Boots in Brown Chromexcel

Chromexcel leather gets the best of both worlds, combining both chrome and vegetable tanning to create something beautiful and unique. The hide is first chrome tanned, then vegetable tanned using Horween’s proprietary recipe. It is then hot stuffed with waxes and greases, resulting in leather brimming with oils (this type of leather is also known as pull-up leather because the oils migrate when the leather is folded or pulled). It is then finished with hand swabbed aniline dyes that don’t mask the leather’s surface and retain the skin’s natural grain structure. The result is a hide that is both beautiful and durable, and it’s no surprise that Chromexcel’s unique qualities have made it the leather of choice for a number of different goods.

Chromexcel wallets only look better with wear. Chromexcel shoes require little to no break in, as the leather practically molds over your feet (though Chromexcel is best suited for casual footwear because it doesn’t take a shine the same way traditional calfskin does). Chromexcel is also a great choice for watchstraps because the leather is pliable, water-resistant, and develops a patina quickly. By the way, Chromexcel has a number of different variations, and Cavalier Chromexcel is simply a variant that uses a lighter base tannage so that brighter-colored leather can be made (like our Crimson and Rye straps).


Shell Cordovan

There exists plenty of confusion when it comes to shell cordovan. I’ve seen cordovan mistakenly used to describe horsehide; I’ve seen it used to describe color and finish. I’ve even seen corrected-grain leather shoes dishonestly labeled cordovan, with a price tag to boot. It’s no surprise then that many consumers today have a hard time discerning what’s what, and that confusion makes it difficult to explain the premium that true shell cordovan commands.

Alden X J.Crew Captoe Boots

So what is shell cordovan? A common answer given by most is horse butt, but that’s also incorrect. Shell cordovan is technically horse “leather,” but more specifically it is the small membrane of flat muscle found under the skin of a horse’s rump. A single horse can yield two pieces of cordovan, large enough to make one pair of shoes, yet small enough that a cordovan belt needs to be stitched together from several pieces because a single shell is not large enough accommodate a belt’s length. Horween is perhaps best known for their shell cordovan, and it’s the only North American tannery producing the stuff. But before a piece of shell can become a beautiful watchstrap or a pair of hardwearing shoes, it must go through a labor-intensive prep and tanning process.

The hides – the majority of which come from Canada and Europe where the horses are neither bred nor killed specifically for the purpose of leather, but for meat – are brought to the tannery salted to prevent rotting. They are sectioned off, and the general area containing the shell is separated from the rest of the hide. After the hide is cleaned and cleared of all hair, it is tanned in large pits containing Horween’s proprietary tanning solution for no less than 30 days. The hides are then removed so that a specially trained worker can identify and shave off any parts that aren’t shell.

Nomos Club on a Nomos Shell Cordovan Strap

The remaining hide is then pit tanned for another 30 days in a stronger solution, where it is agitated to ensure uniform penetration of the compound. After the tanning process, the shell is nourished with a blend of oils and greases that are pounded into the leather. It is then hand oiled and allowed to hang dry for 90 days, during which the oils slowly soak into the leather. Finally, the shell pieces are stained, glazed using old-fashioned glass jacks, and pressed. Done properly, this process takes no less than 6 months.

The end result? A special hide that is not only beautiful, but also tremendously durable. It stands up to water much better than cowhide does, so the material is perfect for those rainy days. It’s also great for winter shoes and boots because cordovan, due to its non-porous nature, wears warm. And if the weather is particularly bad and your shoes are covered in grime, the maintenance can be as simple as a wipe down with a wet cloth and couple of swipes from a horsehair brush (shell is packed with so many oils that conditioning is rarely necessary). And for those of us who prefer leather to metal bracelets, cordovan is a great material for watchstraps. It takes to sweat much better than most leather straps, and it maintains its color and luster much better than calfskin so that it is the perfect accompaniment for a dressier timepiece (though it won’t look out of place on a casual watch either).


As I mentioned before, other leather is sometimes masqueraded as shell, so it’s important to keep a vigilant eye when shopping around. The easiest way to tell if what you’re dealing with is shell cordovan is to observe how the material creases. Shell doesn’t crease the same way most leathers do. Calf tends to have small, sharp creases; shell does not. Instead, it “ripples,” creating soft, wide, wave-like bends. You won’t see this rippling effect on watch straps, but it will be visible on footwear after the first wear.


Now that you know what Chromexcel and shell cordovan are, you have to ask yourself if the product is worth the price. I would personally pay a premium for straps made of genuine shell cordovan and Horween Chromexcel because I know that I am getting some of the best leather out there. I also know that it can be difficult to drop a lot of money on a leather strap–especially if that strap takes away from future watch purchases–so here is a quick rundown of what’s available.

Rios Cognac Cordovan Strap

With regard to shell cordovan, there are a lot of options out there, three of which are Leffot, Hodinkee, and us. All three are American-made, though we’ve opted for shell hides from a small tannery out of Italy due to its impressive array of colors. Nomos also offers another option for Horween shell as does the German strap maker Fluco. On the slightly cheaper end, you can get a German-made Rios strap in a couple of different colors, though I am fairly certain they use a stiffer shell sourced from Japan.

Our High Craft – Vintage range.

There are also a number of options out there when it comes to Chromexcel, from craftsmen and women on Etsy to countless Ebay options. The worn&wound shop also has a collection of American-made straps featuring Horween leather uppers, like our Model 1, Model 2 Premium, and our most recent High Craft – Vintage series. Now that you know what’s what, go out there and make some smart purchases. For those of you who have some nice shell Cordovan or Chromexcel products, show them off in the comments section. A picture is worth a thousand words.

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Ilya is Worn & Wound's Managing Editor and Video Producer. He believes that when it comes to watches, quality, simplicity and functionality are king. This may very well explain his love for German and military-inspired watches. In addition to watches, Ilya brings an encyclopedic knowledge of leather, denim and all things related to menswear.