What Is Twill?

How is twill made?

Twill is made on a loom by lifting the lengthwise warp threads in a pattern that shifts by one thread on every pass of the crosswise weft, so the floats line up into a diagonal. Weft is also called filling, and each pass is a pick. In a 3/1 twill, each warp yarn goes over three picks and under one. The next warp yarn repeats that sequence, advanced by one pick, and the repetition builds the twill line.

The numbers name the float. The first is how many picks a warp yarn passes over and the second how many it passes under. In denim weaving, machines running 2/1 fabric use three or six harnesses (the frames that lift the warp) for the ground weave, and machines running 3/1 or 2/2 fabric use four or eight.

Which way the diagonal runs

A twill line that rises from lower left to upper right is a right-hand twill; one that rises to the left is a left-hand twill. In a regular twill the line climbs at about 45°, and weavers vary both the direction and the angle to make other effects.

The main twill structures

Twills are also grouped by which yarn dominates the face: warp-faced twills show more warp on the face, weft-faced twills show more weft, and even-sided twills show the same amount of warp and weft on both sides. Cloths commonly woven as twills include gabardine, serge, drill, denim, surah and sharkskin.

What are the properties of twill?

Twill gives a strong, durable cloth that is less inclined to wrinkle or show soil than a plain weave, with diagonal ribs on the face and a smoother back. Plain weave, by contrast, passes each filling yarn over and under each warp yarn, with each row alternating. That produces a high number of intersections. Unprinted plain-weave cloth has no right or wrong side, does not ravel easily and tends to wrinkle.

The weave is only half the story. The fibre, the yarn and the finish shape much of the rest, so a cotton twill and a wool twill behave very differently. Yarn twist also changes the look and hand: in denim, a warp yarn twisted in the opposite direction to the twill line gives a more pronounced line and a slightly softer hand.

How is twill graded or measured?

Twill has no single grade; it is described by its float notation, its direction and the weight of the finished cloth. A specification such as “3/1 right-hand twill, 14.5 oz” tells you the structure, which way the line rises and how heavy the fabric is.

For denim, Cotton Incorporated gives a finished range of 3.5 to 16.5 ounces per square yard. It assigns 3.5–8.0 oz to blouses, tops and shirts, and 8.0–16.5 oz to trousers, jeans, jackets and upholstery. Check the unit before you compare cloths.

How does twill appear on a clothing label?

Twill never appears as the fibre content, because it is a weave; the label must name the fibres the twill is woven from. In the US, most textile products need a label giving fibre content and country of origin. It must also identify the manufacturer or another business that markets or handles the item, by company name or RN. Fibres are listed by generic name and percentage by weight in descending order, with a 3% tolerance on blend percentages and none on a single-fibre claim.

• Small amounts (US): fibres under 5% are generally listed as “other fiber”, unless the fibre has a definite functional significance at that amount. A stretch twill of 97% cotton and 3% spandex may therefore name the spandex.
• Wool (US): wool or recycled wool must be named with its percentage even below 5%.
• EU: only the fibre names listed in Annex I of Regulation (EU) No 1007/2011 may be used, and multi-fibre products must list every fibre with its percentage by weight, largest first (with limited room for an “other fibres” entry). A “100%” or “pure” label allows no more than 2% extraneous fibres (5% for carded products) when these are technically unavoidable.

A label reading “65% polyester, 35% cotton” on a twill shirt tells you the fibre mix; the word twill on the swing tag or product page tells you only the weave.

How do you tell good twill from poor twill?

Good twill shows a clean, continuous diagonal on the face, a structure and weight that suit the garment, and a fibre label that matches what the seller claims. Five checks you can make in a shop:

1. Find the face. Look for parallel diagonal ribs on the outside and a smoother reverse. If both sides look identical and there is no diagonal at all, the cloth is a plain weave, not a twill.
2. Read the direction. Hold the cloth with the warp running vertically. A line rising to the right is a right-hand twill, to the left a left-hand twill. A deliberately broken or reversed line (broken twill, herringbone) is a design choice, not a fault.
3. Count the float. With a magnifier, follow one warp yarn. Over three picks and under one is a 3/1 twill, with a warp-coloured face; that is why 3/1 indigo denim, whose warp is dyed and filling left undyed, is blue on the face and pale on the back. Over two and under two is a 2/2 twill, showing warp and weft almost equally.
4. Check the weight against the use. Ask for, or read, the weight. A denim under 8 oz per square yard sits in the shirt and blouse range; trousers, jeans and jackets sit at 8 to 16.5 oz.
5. Read the fibre label, not the fabric name. Names like gabardine, serge or drill describe a cloth construction, not a fibre, so the label is the only reliable guide to what you are paying for.

Red flags: a garment labelled only “twill” with no fibre percentages, which does not meet US or EU fibre-labelling rules; a single-fibre “100%” claim you cannot square with the swing tag or product description; and a twill line that wanders or skips across a panel where the design calls for a straight one.

What is the difference between twill and plain weave?

Twill steps its interlacing to form diagonal ribs, while plain weave alternates over one and under one with no diagonal and no right or wrong side.

Some cloth names need a closer look. The Museum of Fine Arts, Boston’s CAMEO database lists “some tweeds” among twills, and the tweed entry explains the weaves used. Unsure whether a shirting sold as broadcloth is a twill? Look at the face. A twill shows a diagonal; a plain weave does not.

How do you care for twill?

Care twill according to its fibre, and follow the care label. In the US, care labels on clothing are required by a separate FTC rule, the Care Labeling Rule (16 CFR Part 423), and the fibre content may appear on the same label. A cotton twill, a wool twill and a polyester twill can need entirely different washing, drying and pressing.

Is twill sustainable?

Twill is a weave, not a material, so the word on its own says nothing about a garment’s environmental impact. Judge a twill garment by its fibre label and by what the maker can tell you about how the cloth was produced.