There's a major distinction to draw here right off the bat: In the world of Italian tailoring it’s Naples against (or at least, compared to) everywhere else in Italy (Milan and Rome in particular).

The latter, generally speaking, favor a powerful, elegant silhouette with a fair amount of flash—closely-cropped jackets, large lapels and fabrics that are inky and rich. Roman tailoring was developed from British tradition in the late 19th and early 20th centuries, slowly growing into its own lightly adjusted style that favored a sleek, slim, structured look. Today, though, most suit makers are headquartered in Milan along with most of Italy's fashion operations.

Armani is one of the most iconic suit makers to operate in this tradition, becoming a household name in the ‘80s for bringing a broader, architectural upper body (three-button jackets, heavily padded shoulders, full chests) to suits that came to be favored by Hollywood and Wall Street types. Armani still exists, of course, but their suit offerings now are divided between the brand’s several sub-labels, and even the top-of-the-line offerings (Giorgio Armani, aka Black Label) are of questionable construction quality and taste relative to their price tag. Zegna and Brioni are two of the more worthy labels to make their suits in the traditional Italian style; both are said to be of exceptional quality with fine wool and careful handwork, but an unassuming profile. Dark fabrics, notch lapels, two buttons, flat-front trousers with belt loops are notable details to this style—a very "normal" suit, at least by today's standards.

In Naples, they do things quite differently. Neapolitan tailoring began in earnest in the mid-20th century and evolved into its own kind of elegant, entirely unique style apart from the suits that were being made elsewhere in Italy. These suits are distinctive for their soft, unstructured profile and rumpled shoulder, where a greater amount of fabric on the upper arm is gently draped into the armhole of the jacket to create a puckering effect. Other hallmarks of the style include: a high armhole for easy movement, exceptionally light and fine fabrics with minimal or no lining (better for braving the hot and humid Neapolitan weather), an extended front dart on the jacket, wide lapels, a 3/2 roll button stance (tre buttoni su due in Italian), patch pockets, a curved chest pocket (called barchetta, or boat-shaped) and double stitching along the jacket's lapels and pockets. It's light and comfortable, while maintaining an air of easy elegance. You're also more likely to find these in bold colors with attention-grabbing details. The bright and breezy showgoers of Pitti Uomo, despite taking place in Florence, are excellent examples of the Neapolitan style in practice.

The Basic Style: For Neapolitan suits, light and soft with distinct technical flourishes and, often, bold colors. For other Italian suits, simple and elegant with slim fits. Generally speaking, often plays on the concept of an "inverted triangle" body shape. Wide lapels contrast against a trimmer waist, with slash pockets and usually no vent on the jacket.

Notable Brands: Kiton, Brunello Cucinelli, Isaia, Ermenegildo Zegna, Brioni, Armani, Lardini

Ever seen old movies from the '50s and '60s, where every guy is wearing a generously-cut suit? That's a great visual reference for the tradition that American tailoring is anchored in. The United States' suit making is largely rooted in the the "sack suit," popularized (though likely not invented) by Brooks Brothers. They introduced a suit they called the "Number One Sack Suit" in 1901, which became the go-to garment for American men for decades.

Brooks' take on the jacket omitted darting in the jacket, creating a flatter and more boxy fit. The sack suit also used a 3/2 roll lapel, which, while also prominent in Neapolitan tailoring later in the century, was likely born in America in the early 1900s. The story goes that university students grew tired of their traditional three-button suits, but, being too broke to afford entirely new suits, simply pressed their lapels to roll over the top button to mimic the two-button style that was growing in popularity at the time. Brooks Brothers took note and incorporated the look into its off-the-rack suiting. Jacket canvassing tended to be stiffer, and shoulders were lightly padded—somewhere in between the totally natural look of Neapolitan suits and the heavily-roped styles of Savile row.

The sack suit is a huge part of the inspiration for Thom Browne's suiting, which single-handedly reshaped American tailoring in the 2000s, Browne’s tradition (and resume—his Black Fleece line is no coincidence) may draw from vintage Brooks Brothers, but his cut is almost comically shrunken, stylized and thoroughly modern.

Other American tailors now cover a large spectrum of styles with international influence: Tom Ford, one of the most notable names in suiting, favors exaggerated silhouettes with big peak lapels, ticket pockets and powerful shoulders that are much more Savile Row than sack suit. When it comes to Tom Ford, think “power suit.”

Ralph Lauren still makes gorgeous and largely traditional American suiting, but with some significant Italian influence like roped shoulders, a trim yet soft jacket construction and exceptionally fine wool. Nowhere is this more visible than within its top-of-the-line Purple Label offerings (the suits are made, in fact, in Italy). Polo suits, meanwhile are more traditionally American with a naturally sloped shoulder and slightly sturdier wool. RRL suits are all over the place, with unstructured jackets and patch pockets on some cuts and 3/2 rolls with waistcoats and powerful peak lapels on others. Much like Ralph Lauren as a brand—and, arguably, America's tailoring tradition as a whole—these suits have adopted, molded and combined Italian and British influences into something new.

Sid Mashburn makes a similarly modern interpretation, with an homage to the sunny Neapolitan style through the lens of the equally hot-tempered American South. Hickey Freeman still makes fantastically traditional American suiting out of Rochester, New York, and J.Crew still makes solid and classically American options (fitting for the American man on a budget, not unlike those Ivy League University students roughly a century ago).

The Style: Traditionally, a straight fit, lightly padded shoulders, notch lapels, 3/2 roll button stance and a single center vent. Now, though, styles are all over the place.

Notable Brands: Sid Mashburn, Thom Browne, Ralph Lauren, Brooks Brothers, Hickey Freeman, Brooklyn Tailors, J.Crew

British tailoring has plenty of noteworthy names dotting the addresses of Savile Row, all with rich histories and fairly distinctive house styles. So it's difficult to make sweeping statements about a British style in general. Huntsman, for example, has an exceptionally trim cut with a nipped waist and flared jacket skirt, one-button closure and strongly roped shoulders set with high armholes—inspired by the label's centuries-old old history as a military and hunting outfitter. Anderson & Sheppard, on the other hand, favors a much fuller drape and subtle detailing with a more natural shoulder and a construction that's not too architectural.

There are, however, some constants that can be generally said to be British, whether or not certain English tailors tend to follow in the tradition. Strong and padded roped shoulders, side vents, stiffer jacket canvassing, ticket pockets, a lower gorge line (i.e. a lower button stance. Italians, on the other hand, prefer this to be higher) and a little more structure across the suit overall when compared to Italian or American suits.

Savile Row suits are thought of as strong, proud, exceptionally precise garments, often with close cuts and meticulous hand-stitched detailing. Several of the earliest shops, including the founding member of Savile Row tailors, Henry Poole, have histories as military outfitters, a reference point that has perhaps helped to define this kind of British tailoring throughout the late 20th century. That’s likely how you arrive at what’s considered to be the British style: strong shoulders, stiff and exactingly measured silhouettes, and closely-cropped fits are hallmarks of Savile Row suit making, as are more formal and ornamental flourishes like waistcoats and double-breasted jackets.

The Style: Variable, but generally more military-inspired, heavily-structured jackets with stiffer silhouettes and strong shoulders. As Savile Row's fame proves, these suits generally have a very "tailored" (see: sliming) look, boasting double vents on the jacket (a touch that harkens back to the needs of horse riders) with flap pockets.

Notable Brands: Gieves & Hawkes, Anderson & Sheppard, Kilgour, Huntsman, Henry Poole