Suit Fabrics Explained: Wool, Linen, Cotton, Mohair, Silk and Blends

Suit fabrics decide more about how a suit feels than any other choice you make at a tailor. The fiber sets how it breathes and creases, the yarn and weave set how it drapes and wears, and the weight sets the season. A beautifully cut suit in the wrong fabric will still feel hot in July or look tired by noon. Start with wool, the default, then work through the alternatives for heat, cold and budget.

What is the best fabric for a suit?

Worsted wool is the best fabric for most suits. It breathes, absorbs moisture vapor, springs back from creases, takes a sharp press and lasts for years with basic care. A mid-weight worsted in navy or gray works for the office, weddings, interviews and travel, which is why tailors treat it as the default.

The other fibers earn their place in specific conditions. Linen and cotton are cooler and more casual. Mohair adds crispness and luster for heat and evening wear. Cashmere and woolen flannels add softness and warmth for winter. Polyester costs less and resists creasing but gives up comfort. The table compares them on the points that matter when you wear a suit all day.

Wool: the default suit fabric

Wool is the fiber of almost every tailored suit. Each fiber has a natural crimp, a wave along its length, which gives the fabric spring: a wool sleeve creased at the elbow recovers overnight on a hanger. Wool also absorbs water vapor into the fiber itself, so it copes with sweat better than synthetics, and it resists odor, so it needs cleaning far less often than cotton. For a tailor, wool's biggest virtue is that it can be shaped with steam and an iron, which is how a jacket gets its curved chest and rolled lapel.

Most fine suiting wool comes from merino sheep. What turns that fiber into very different fabrics is how it is spun, how fine it is and how it is woven.

Worsted and woolen yarns

Worsted yarn is combed so the long fibers lie parallel, giving a smooth, strong, crisp yarn; most business suits are worsted. Woolen yarn is carded only, so the fibers stay jumbled and the yarn is fuzzier, loftier and warmer. Flannel and tweed are the classic woolen fabrics, though worsted flannel also exists. Our guide to worsted vs woolen wool explains both.

Super numbers

A label such as Super 120s states how fine the wool fibers are. Under the code of practice of the International Wool Textile Organisation (IWTO), Super 120s means a mean fiber diameter of no more than 17.75 microns. Higher numbers feel softer but crease more and wear faster, so Super 100s to 130s is the sweet spot for suits you wear often. Our guide to Super numbers has the full micron chart.

Common wool weaves

The weave changes how a wool fabric looks, breathes and wears. These are the ones you will meet in a fabric book.

How heavy should suit fabric be?

Fabric weight is the clearest guide to the season a suit is for. It is quoted per running length of fabric: English mills give ounces per running yard and Italian mills give grams per running meter, and 1 oz is about 31 g. A 10 oz English fabric and a 310 g Italian one weigh roughly the same.

Heavier fabrics drape and resist creasing better, because their own weight pulls the garment straight. Lighter fabrics are cooler but wrinkle more and show the outline of anything underneath, such as a phone in a pocket. For a first suit, our guide to the best year-round suit fabric recommends about 10 oz (310 g).

Linen

Linen is made from the stalks of the flax plant. It is the most breathable suit fabric and the coolest to wear in dry heat: it carries heat away from the body, absorbs moisture and dries quickly. Its weakness is creasing. Linen fibers have very little elasticity, so every bend leaves a mark, and a linen suit looks lived-in within an hour.

Weight changes that. Light linens of 7 to 8 oz (220 to 250 g) crease the most; heavier linens of 11 oz (340 g) and up, a traditional strength of Irish mills, crease less and hang better. Blends with wool or silk keep most of the coolness with fewer wrinkles. Linen is a daytime, warm-weather fabric: right for summer weddings and holidays, less so for formal business. Read our full guide to linen suits.

Cotton

Cotton suits use the same plant fiber as shirts, woven heavier and tighter: twill and gabardine for chino-style suits, poplin for light summer suits, and seersucker, whose puckered stripes hold the fabric away from the skin. In winter, cotton appears as corduroy and moleskin, both dense and warm.

Cotton breathes well and feels cool and dry to the touch, but it soaks up sweat and dries slowly, so it can feel damp in humid heat. It creases, though less sharply than linen, and it lacks wool's spring, so knees and elbows bag. It also fades with sun and cleaning. That makes cotton a relaxed, daytime fabric. Tan, stone, olive and mid-blue are the classic colors.

Mohair

Mohair comes from the Angora goat (angora, confusingly, comes from the Angora rabbit). The fiber is smooth, lustrous and very resilient, so mohair fabrics spring back from creases, feel crisp and dry against the skin, and stay cool in heat. In suiting it is almost always blended with wool, which softens its wiry hand.

Mohair blends are among the best fabrics for humid heat and for evening wear, where their slight sheen looks deliberate. The trade-offs: the luster reads as shiny to some eyes, the hand can feel a little scratchy at first, and good mohair is expensive. It is one of the fabrics we rank highest for heat, alongside high-twist wool and linen.

Silk

Silk is the fiber spun by silkworms. Pure silk suits are rare, because silk creases, marks with sweat and wears at friction points. Instead, silk is blended with wool and linen, where it adds luster, a cool smooth hand and, as raw or slubbed silk, the irregular texture seen in summer sport coats. A wool, silk and linen blend is one of the classic warm-weather jacket fabrics: cooler than pure wool and less creased than pure linen.

Expect silk blends to cost more and to need gentler care. They suit sport coats and summer suits better than hard-working business suits.

Cashmere and other luxury fibers

Cashmere is the fine undercoat of the cashmere goat. It is softer and warmer than sheep's wool of the same weight, which makes it superb for winter jackets and overcoats. It is also less resilient: pure cashmere pills, wears through at the elbows and seat, and loses its shape sooner than worsted wool. For suits, a small proportion of cashmere blended with wool gives much of the softness while keeping wool's durability.

Alpaca, vicuña and other rare fibers appear in jackets and coats at the top of the market. They are a pleasure to wear and a poor choice for trousers you sit in every day.

Polyester, viscose and other synthetics

Polyester is a plastic fiber. It is cheap, strong against abrasion and very crease-resistant, which is why it dominates budget suits and uniforms. It is also uncomfortable: it absorbs almost no moisture, so sweat stays on your skin, it can look shiny, especially after pressing, and it pills. Wool blends with a little elastane or polyester exist for travel, and they are a reasonable compromise, but pure wool remains best for comfort. Our polyester vs wool comparison covers blends, stretch and how to spot polyester.

Viscose (rayon) is a regenerated fiber made from wood cellulose. It drapes softly and breathes better than polyester, but it creases and can lose its shape when damp. You will find it in cheaper suits. Cupro, a related regenerated fiber best known under the Bemberg brand, is a breathable lining many tailors prefer; see suit linings explained. Elastane (spandex) is added to wool in small amounts, usually a few percent, for stretch.

Blends: when mixing fibers makes sense

A blend combines fibers to borrow their strengths. Good blends are made with a clear purpose, such as adding coolness or crease resistance; poor ones add a cheap fiber to cut cost.

Which suit fabric for which climate and season?

Match the fabric to where and when you will wear it. This matrix shows how each common option performs, assuming a sensible weight for the fabric type.

Heat is where fabric matters most. For hot climates, see the best suit fabric for hot weather and our practical guide to staying cool in a suit.

What suit fabric is best for everyday wear?

For a suit you wear several days a week, choose a worsted wool in Super 100s to 130s, about 10 oz (310 g), in a plain weave or fine twill, in navy or mid-gray. That combination resists creasing, survives daily sitting and commuting, and can be pressed back into shape. Avoid Super 150s and above for daily wear: they feel wonderful and wear out at the seat and elbows far sooner.

Common suit fabric mistakes

• Buying the highest Super number you can afford. Fineness is not quality, and very fine fabrics wear faster.
• Choosing linen for a crisp look. Linen will crease. If you need to look pressed at 5 pm, choose high-twist wool or a mohair blend.
• Judging heat by color alone. A dark open weave is cooler than a light, dense one.
• Ignoring weight. The same navy wool at 8 oz (250 g) and at 13 oz (400 g) makes two different suits for two different seasons.
• Paying wool prices for a polyester blend. Read the fiber label before you look at the price.
• Choosing from a tiny swatch. Stripes and checks look bolder over a whole jacket. Ask to see a larger piece in daylight.

The tailor's view: how to choose from a fabric book

At a good tailor you will be handed fabric books (swatch books) from several mills, often dozens of pages each. A good tailor narrows the choice with questions before showing you anything. If yours does not, work through these steps.

English and Italian mills

Fabric books come from mills and merchants in England, Scotland, Italy and elsewhere. As a broad tendency, English and Scottish fabrics are firmer and drier, made to tailor crisply and last, while Italian fabrics are often softer, lighter and more lustrous. Neither is better. Firmer fabrics suit structured tailoring and hard daily wear; softer ones suit lighter, less structured jackets. Ask your tailor which fabrics they like working with: they know which ones press well and which ones fight back.

If you are buying one suit, start with mid-weight worsted wool and add every other fabric later, for a purpose. When you are ready to commission, our ranking of the best tailors in London shows where to find a wide choice of fabric and the advice to match it.

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