Super 100s, 120s, 150s, 180s: the numbers that appear on the labels of high-end suits suggest a hierarchy of quality—the higher the number, the better. The reality is more nuanced. This number does not measure the quality of the wool, but rather the fineness of its fibers. And beyond a certain threshold, fineness becomes a trade-off.
“Super”: What This Number Really Measures
“Super,” followed by a number, is an indication of fiber fineness expressed in microns; it is not a measure of overall quality. The system was established by the International Wool Secretariat in 1968 to standardize the description of wool. The higher the number, the finer the fiber—but fineness is not synonymous with quality; sometimes the opposite is true.
The Super number appears on virtually all high-end suit labels. Its original purpose was purely technical: to allow professional buyers to compare fabrics from different spinning mills on a common basis. The system, established in 1968 by the International Wool Secretariat (IWS, later renamed Woolmark), establishes a direct correspondence between the Super number and the maximum diameter of the fibers used in weaving.
Super 100s wool contains fibers with a diameter of no more than 18.75 microns. Each higher grade—110s, 120s, 130s—represents a reduction of approximately 0.5 microns. Super 130s corresponds to fibers of 17.25 microns or less; Super 180s, to 14.75 microns. By way of comparison, a human hair measures between 60 and 100 microns: even standard suit wool is three to six times finer. The “Super” number does not indicate anything else. It does not indicate the origin of the wool, the weight of the fabric, or the quality of the weave.
Frequently Asked Question: What exactly does the “Super” number on a suit label mean?
“Super” followed by a number indicates the maximum fiber diameter in microns. Super 100s = 18.75 microns; each increment of ten reduces the diameter by approximately 0.5 microns. The number measures only the fineness, not the overall quality of the fabric—which also depends on weight, origin, finish, and weave.
Tailor’s Tip: Check to make sure that a premium suit label includes a “Super” number. Its absence isn’t necessarily a bad sign (very high-quality English fabrics and some Italian ones don’t always include it), but it prevents a technical comparison between two fabrics. A brand that doesn’t specify “Super,” weight, or origin is harder to evaluate than one that provides all three pieces of information.
Microns and Feel: The Physical Interpretation of the Number
Super 100s wool has fibers measuring approximately 18.75 microns; Super 150s wool, approximately 16.25 microns. This difference—less than three microns—radically changes the feel: the finer wool is softer, silkier, and drapes better. However, it loses some of its structure and durability.
A difference of just a few microns is enough to transform the feel of a fabric. Super 100s wool has a crisp, slightly rough texture that gives the jacket its structure. Super 130s wool becomes noticeably softer without losing its shape. Starting with Super 150s, your hand literally glides over the fabric—a texture close to silk, with an immediate fluidity. Beyond Super 180s, the fabric feels almost like pure cashmere.
This gradual softness is clearly reflected in the drape. The finer the fiber, the more the fabric falls in soft, fluid, almost liquid folds. Super 100s to 120s wools hold their shape well; Super 150s and higher drape more freely, and some very fine fabrics lose their shape as soon as they are sat on or creased. The difference is immediately apparent to the eye, right from the first try-on. Choosing a Super grade also means choosing a silhouette.
Frequently Asked Question: How many microns, according to Super?
Super 80s: up to 19.75 microns. Super 100s: 18.75. Super 110s: 18.25. Super 120s: 17.75. Super 130s: 17.25. Super 150s: 16.25. Super 180s: 14.75. Super 200s: 13.75. Each ten-unit increment reduces the fiber diameter by approximately half a micron. Beyond Super 200s, the fibers become so fine that they are often blended with other materials (cashmere, silk, vicuña) to maintain a minimum level of structure.
Tailor’s tip: To feel the difference between two fabric weights in a store, ask to touch two fabrics side by side that have the same weight but are Super-rated differently—a Super 110s and a Super 150s, for example. Your hands will immediately sense the difference in silkiness and smoothness, whereas a verbal description remains abstract. This hands-on comparison is worth more than any sales pitch.
The Inverted Curve: Sophistication vs. Durability
The finer the fiber, the more delicate it is. Super 180s wool feels wonderful to the touch but wears out more quickly, wrinkles more easily, and is less suitable for everyday wear. The finest wools aren’t the most practical: they’re more suited to formal wear than everyday suits.
The mechanical strength of a wool yarn decreases as its fineness increases. A 14.75-micron yarn—Super 180s—is physically more fragile than an 18.75-micron yarn. In practical terms, this fragility manifests in three ways: more pronounced wrinkling (the fiber does not regain its shape as well), accelerated wear at points of friction (elbows, knees, and the seat of trousers), and increased sensitivity to moisture and the heat of dry cleaning.
A Super 180s suit worn every day may begin to show these signs after one or two seasons: the fabric starts to shine in areas of friction, creases deepen, and the sleeves retain the marks of repeated wear. A Super 110s suit, worn just as often, will last several years without these flaws. The rule is consistent: very fine-count fabrics are best suited for occasional wear, not for a suit worn three times a week.
Frequently Asked Question: How long will a Super 180s suit last with daily wear?
It’s unlikely to last more than one or two seasons without visible signs of wear. Very fine-weight fabrics are designed for occasional wear—ceremonies, special events, and formal attire. For a suit worn several times a week, sticking to the Super 100s to 130s range significantly extends the garment’s lifespan.
Tailor’s tip: A Super 150s suit—or higher—deserves a second suit to wear on a rotating basis. Letting a high-end suit “breathe” between wears—24 to 48 hours on a shaped hanger—cuts wear and tear in half and preserves the fabric. This simple practice often doubles the lifespan of a fine fabric suit.
The sweet spot for everyday wear: Super 110s to 130s
For an everyday suit, the Super 110s to 130s range offers the best balance between a fine feel, elegant drape, and true durability. This is the range in which the majority of high-quality wardrobe fabrics fall, and the one RIVES recommends for a first signature suit.
The Super 110s to 130s range—corresponding to fibers measuring 18.25 to 17.25 microns—accounts for virtually all high-end professional suit fabrics. The fabric feels very comfortable against the skin, and its drape remains excellent; the drape combines structure and suppleness without becoming shapeless. The leading Italian (Loro Piana, Vitale Barberis Canonico, Reda) and British (Dormeuil, Holland & Sherry, Scabal) mills produce their most structured collections within this range.
The cost of a Super 110s to 130s fabric remains reasonable given its performance: significantly lower than that of a Super 150s fabric, while often offering equal or superior wearability for everyday use. It is this range that forms the basis for most of RIVES’ recommendations for a first tailor-made suit—whether for the office, a versatile formal occasion, or travel. Fabric choices are therefore based on weight and season (see the article on flannel, fresco, and twill) rather than on the pursuit of the highest Super number.
Frequently Asked Question: Which Super should I choose for an everyday office outfit?
Choose between Super 110s and 130s for use three to five times a week. This range offers a premium feel, a well-defined drape, and a lifespan of eight to fifteen years with proper care. Going beyond this range offers only marginal improvement in tactile comfort, at the cost of increased fragility and a significant additional expense.
Beyond Super 150s: Luxury, Formal Wear, Blends
Super 150s to 200s wools are intended for other uses: formal occasions, special events, and casual wardrobe pieces. For wools above Super 200s, manufacturers often blend the wool with cashmere, silk, or vicuña—both to preserve softness and to add qualities that wool alone cannot achieve.
Very fine-count fabrics have their place. A suit for a civil wedding or a tuxedo worn three or four times a year fully justifies a Super 150s or 160s fabric, whose fluid drape is well-suited to evening occasions and whose occasional wear does not reveal the fabric’s fragility. Loro Piana, Cerruti, and Dormeuil offer collections designed specifically for these purposes, often in limited editions.
Beyond Super 200s, manufacturers enter exceptional territory where wool alone reaches its mechanical limits. To maintain the fabric’s structure, high-end spinning mills blend wool with other precious fibers—cashmere for softness and drape, silk for luster and suppleness, and vicuña for the rarest compositions. These blends are not a compromise: they are the only way to produce a fabric suitable for use at these levels of fineness. Suits made from these fabrics are more akin to works of art than to everyday wardrobe staples.
Frequently Asked Question: When should you choose Super 150s wool or higher?
For a suit worn on special occasions—weddings, formal events, or as part of a formal wardrobe—where feel and drape take precedence over durability. For a suit worn a few times a year for special occasions, a Super 150s fabric makes sense; beyond that, the choice becomes more about aesthetics than practicality.
Beyond “Super”: Weight, Origin, Finish
The “Super” number says nothing about the fabric’s weight, the origin of the wool, or the finishing process—three factors that are at least as important when evaluating a suit fabric, and which reputable brands always specify in addition to the “Super” number.
The weight of a fabric, measured in grams per square meter, influences the drape just as much as its fineness. A fabric weighing 220 to 250 grams is a summer fabric—fresco wool, mohair, or lightweight blends. Between 280 and 320 grams, we enter the transitional season range, the most versatile category. Above 320 grams, we move into winter fabrics—dense flannel, sturdy fabrics, and structured woolens. This weight classification is independent of the “Super” rating: a Super 130s fabric can weigh 240 grams for summer or 320 grams for winter.
The origin of the wool also matters. Australian merino remains the market benchmark—long fibers, consistent fineness, and carefully managed farming. New Zealand also produces very high-quality wool, sometimes with specific textural nuances. More rare, Patagonian wool provides certain batches prized for tuxedo fabrics. The finishing process—combing, polishing, and fulling—ultimately distinguishes two fabrics of the same Super and weight: a poorly finished fabric loses its luster and structure after just a few cleanings. The supplier’s name (Loro Piana, Vitale Barberis Canonico, Reda, Dormeuil, Holland & Sherry, Scabal) remains the most reliable indicator of the rigor with which these three parameters are combined; the story of RIVES fabrics details this approach in depth.
Tailor’s tip: Before choosing a fabric, ask for three pieces of information that must be clearly provided: the Super number, the weight, and the supplier’s name. A label that includes all three of these details allows for an informed decision; a label that lacks any of them falls short of the standards of premium tailor-made tailoring.
Conclusion: Thinness is not a quality
The fineness of a wool is just one factor among many—and can even become an obstacle when looking for a suit for everyday wear. Choosing a wool means balancing factors such as texture, drape, durability, weight, and intended use. The Super number is just a starting point.
The tendency to buy the highest-end “Super” option is fueled by certain brands that use it as a selling point. The reality of high-quality tailor-made clothing is more nuanced: a reputable tailor advises their client based on the intended use, how often the suit will be worn, the client’s body type, and their budget—and the majority of their recommendations fall within the Super 110s to 130s range, which offers the best long-term value. Very high-grade Super wool does exist and has its place, reserved for occasional or formal wear. To delve deeper into what truly determines the value of a suit, the articles on tailor-made suits and interlining expand on this exploration of the invisible layers of a well-made garment.
Final tip: Before ordering your next suit, ask your tailor three questions about the fabric— “What Super, what weight, and what supplier? What purpose does this range serve? And what trade-offs would there be if I wanted to go with a higher fineness?” ” A tailor who clearly answers all three questions—without automatically pushing for the highest number—is a tailor who has your best interests at heart. An argument that reduces the choice to just the Super rating overlooks a quarter of the factors that ultimately determine a suit’s true quality.