Super Numbers
A grading system for worsted wool that measures fiber fineness in microns. Higher Super numbers (100s, 120s, 150s) indicate finer fibers, softer hand feel, and greater luxury, but also increased fragility.
Super numbers are a standardized grading system used to classify the fineness of worsted wool fibers. Established by the International Wool Textile Organisation (IWTO), the system measures the maximum mean fiber diameter of the wool in microns. A Super 100s wool has fibers no thicker than 18.5 microns, while Super 150s indicates fibers of 16.0 microns or finer. Higher Super numbers mean finer fibers, which produce a softer hand feel, more refined drape, and a smoother visual appearance. However, finer fibers also mean reduced durability and greater susceptibility to wear, wrinkling, and pilling. Understanding this trade-off is essential for recommending the right fabric to each client.
The Micron Scale
The Super number system follows a specific micron scale defined by the IWTO. Super 80s corresponds to fibers of 19.5 microns or finer. Each step of 10 in the Super number reduces the maximum fiber diameter by approximately 0.5 microns: Super 100s is 18.5 microns, Super 110s is 18.0, Super 120s is 17.5, Super 130s is 17.0, Super 140s is 16.5, and Super 150s is 16.0. Beyond Super 150s, the increments continue but the practical differences become increasingly subtle. For context, a human hair is typically 50 to 70 microns in diameter, so even a Super 80s wool fiber is roughly one-third the thickness of a hair.
Performance Trade-Offs
The relationship between fineness and performance follows a clear pattern. Fabrics in the Super 100s to Super 120s range offer an excellent balance of softness, durability, and wrinkle resistance. This is the sweet spot for everyday business suits. Super 130s to Super 150s fabrics feel noticeably more luxurious and drape beautifully, but they wrinkle more easily and are less resistant to abrasion, making them better suited for special occasions or clients who do not wear the same suit frequently. Beyond Super 150s, the fabric becomes extremely delicate. Super 180s and Super 200s wools are prized for their incredible softness but are impractical for regular wear. They are the equivalent of a sports car: impressive but not designed for a daily commute.
Common Misconceptions
The Super number is not the only factor that determines fabric quality. Yarn construction, weave structure, finishing techniques, and the specific mill all play critical roles. A well-constructed Super 110s from a top Italian mill like Loro Piana or Zegna will outperform a poorly made Super 150s from an unknown source. Additionally, the Super number only applies to the wool fiber itself, not to blended fabrics. A fabric labeled "Super 130s wool blend" may contain a relatively small percentage of Super 130s fibers mixed with lower-grade wool or synthetic fibers. Always check the full fabric composition.
Choosing the Right Grade
For a daily business suit that will be worn once or twice per week, Super 100s to Super 120s is ideal. The fabric will hold up well over years of wear and dry cleaning while still feeling refined. For a suit reserved for important meetings, events, or occasional wear, Super 130s to Super 150s provides a noticeable upgrade in hand feel and drape. For a statement piece or special occasion suit worn only a few times per year, Super 160s and above delivers the ultimate luxury experience. Price increases significantly with Super number: a Super 150s fabric can cost two to three times as much as a comparable Super 100s from the same mill.
Pro Tip
When presenting fabrics to clients, let them touch and compare a Super 100s and a Super 150s side by side. The tactile difference is immediately apparent and helps justify the price difference. Then explain the durability trade-off so they make an informed choice rather than always reaching for the softest option.
How Sartorly Helps
Sartorly's fabric visualization lets clients see how different fabric grades look on their own image. While the visual difference between Super numbers is subtle, pairing the visual with a tactile in-store experience creates a powerful selling moment that helps clients choose confidently.
Related Terms
Suit Lining
The interior fabric layer of a suit jacket that protects the construction, allows the jacket to slide on and off easily, and adds a hidden design element. Options include full, half, quarter, and unlined.
Canvas Construction
The internal structure of a suit jacket, ranging from full canvas (hand-shaped horsehair interlining) to fused (glued interfacing). The canvas determines drape, longevity, and how the suit molds to the body.
Bespoke
A garment created entirely from scratch for a specific individual, involving a unique pattern, multiple fittings, and hand-finished construction.
Made-to-Measure
A garment produced by adjusting a pre-existing pattern to an individual's measurements, offering a personalized fit without the full bespoke process.
Common Questions About Super Numbers
No. Higher Super numbers mean finer, softer fibers, but also less durability and more wrinkling. The best choice depends on how the suit will be worn. A Super 110s worn daily will look better over time than a Super 150s subjected to the same use. Higher is more luxurious, not universally better.
Super 100s to Super 120s is the ideal range for a first suit. It provides a good hand feel and professional appearance while being durable enough for regular wear. This range is also widely available across price points and fabric collections.
Experienced tailors can often estimate the general range by feel. Super 100s has a smooth, solid hand. Super 130s and above feels notably softer and more fluid. However, yarn construction and finishing can affect hand feel, so touching alone is not reliable for precise grading. Always verify with the fabric specifications.