Why Wool Is the Standard for Suits
Wool is the traditional suiting fibre because it drapes well, breathes, resists wrinkling better than many plant fibres, and can be tailored and pressed into shape. It also comes in a huge range of weights and finishes. Knowing the main types helps you pick suit cloth that fits your climate, budget and sewing skill.
Worsted vs Woollen
The biggest split in suit wool is how the yarn is made.
- Worsted. Long fibres are combed straight and spun tightly, producing a smooth, strong yarn with a crisp surface. Most business suiting is worsted. The word is also used in different ways in different contexts, so check how a seller uses it.
- Woollen. Shorter fibres are carded and spun more loosely, giving a fuzzier, softer, warmer cloth. Flannel and tweed are typical examples.
Common Wool Suit Fabrics
Worsted Suiting
Smooth, versatile and the usual choice for year-round business suits. It holds a crease and presses well.
Fresco (High-Twist Wool)
Fresco, sometimes called tropical wool, is an open-weave, high-twist worsted. It is breathable and often chosen for warm climates.
Flannel
A soft, slightly brushed wool, usually woollen-spun. It is warm and comfortable for autumn and winter.
Tweed
A textured woollen cloth, often in checks or herringbone patterns. It is heavy-duty and suited to casual jackets and sport coats.
Gabardine and Twill
Gabardine is a tight twill weave with a smooth, clean finish and good drape. It is used for suits and trousers.
Merino Wool
Merino refers to the sheep breed and its fine fibre. Merino suiting is soft and often used in high-quality cloth.
Wool Blends
Wool blended with silk, linen, mohair, cashmere or polyester can change the drape, texture or price. Wool-polyester blends are typically cheaper and may resist wrinkles, but may not breathe as well.
What Are Super Numbers?
Super numbers, such as Super 100s or Super 120s, describe the fineness of the wool fibre. A higher number indicates a finer fibre, which usually gives a softer, smoother cloth. Higher is not automatically better: very fine cloth can be more delicate and may wear out sooner under daily use. A mid-range number is often a practical choice for suits worn regularly. Labels can vary in how they are used, so treat the number as one indicator among several.
What Are the Different Grades of Wool Fabric?
Quality is judged by fibre fineness, length, strength and crimp, as well as how the cloth is woven and finished. There is no single universal grade scale for all wool, so a good approach is to examine the label, the mill’s reputation and the feel of the cloth.
Fabric Weight and Season
Suit cloth weight is described in ounces per yard or grams per metre. Roughly:
| Weight | Typical use |
|---|---|
| Light | Summer and warm climates |
| Medium | Year-round wear |
| Heavy | Winter and cold climates |
Specific numeric thresholds vary between mills, so compare within the same supplier or catalogue.
Which Wool Is Best for Suits?
For a first suit, a medium-weight worsted in a mid-range Super number is a reliable all-rounder. For heat, consider fresco. For winter or a relaxed look, flannel or tweed suits well. For luxury, you may explore fine merino or blends with silk or cashmere.
Tips for Sewing With Wool Suiting
- Pre-shrink wool with steam, following the supplier’s advice.
- Use a sharp needle and appropriate thread.
- Press with a pressing cloth and steam to avoid shine.
- Interface and line the jacket for shape.
- Begin with a forgiving cloth such as a medium-weight worsted or a plain flannel before attempting fine, slippery suiting.
For wider context on menswear fabrics, read our guide to fabric for men’s clothes. If you want warmer cloth beyond suiting, see our list of warm fabrics.
Summary
Wool suiting ranges from smooth worsted to cosy flannel and rugged tweed. Understand the yarn type, the Super number and the weight, and you can choose a cloth that fits your climate and how often you plan to wear it.