Weaving Patterns

How are different kinds of cloth made? Different cloths like satins, denims, and twills have different structures feel and look different because they are woven in different ways. The weave pattern – how the warp and the weft threads cross one another – is set in advance and changes how the loom weaves the cloth.

To set up a type of weave, warp threads are fed through harnesses. A harness is the frame that holds the heddles, strips of steel with an ‘eyes’ in the middle. Individual warp yarns, called warp ends, are passed through each heddle. Raising and lowering the harnesses control the warp threads and the weave pattern.

This diagram shows plain weave, which is the most basic weave pattern. A plain weave uses two harnesses, so the finished cloth pattern has weft yarn going over and under the alternating warp threads. Other patterns can get more complicated and require more harnesses.

Dobby loom in the Boott Cotton Mills Museum weave room.

Most of the looms in the weave room are draper model E looms that hold up to four harnesses. That’s enough for many different weave patterns, but not every possible weave. Two of the looms are dobby looms that can hold as many as 16 harnesses. This allows them to make much more complicated patterns

All weave patterns are made from one of three structures: plain weave, twill, or satin. While there are countless different kinds – Oxford, basket weave, herringbone twill, and so on – they are created by making changes to one of these three basic patterns.

Plain Weave

Plain weave, also called plain cloth or tabby, is the simplest kind of weaving. It’s also very common: items like your woven shirts or your bedsheets are often made of plain weave.

Plain weave requires two harnesses, and there are two sheds. Every other warp thread is lifted, while the rest are lowered, allowing the weft to go over one thread, under one thread, over one thread, and so on all the way across the fabric. The next weft thread does the opposite: it goes over the threads the last pick went under, and under the threads the last pick went over.

There are possible variations on plain weave, such as basketweave or Oxford, that make slight changes to this simple structure, like going over two, under two.

This ‘mill girl’ dress, from the Boott Cotton Mills Museum, is made of plain weave fabric, printed in multiple colors with a floral design.

Twill

Twill is another common weave pattern, one that’s a little more complex than plain weave. It requires at least 3 harnesses and works by lifting two at a time in order to stagger which warp threads are passed over or under by the weft thread. There are a lot of different twill variations!

Twills can be identified by the distinct diagonal line created by the staggered skips of the weft.

Why pick a different pattern than plain weave, if other weave patterns are more complicated or require more harnesses? Changing the weave structure changes how the finished cloth looks or feels. The weave pattern helps to determine how stiff or soft a fabric is, how it drapes, and how dense or loose the fabric is. Would you make a ball gown and a bandage out of the same material? What about a sail for a ship? Throughout history – and in the present day – people pick specific weaves based on their properties. What traits of the fabric would be important if you were making a shirt to wear on a sunny day, a covering for the seat of a car, or a backpack? Would you want them to be soft or coarse? Flexible or rigid? Delicate or sturdy?

Take twill, for example: it’s often denser and sturdier than plain weave, so it’s a good choice for cloth that needs to stand up to heavy use or to last a long time. These soldier’s trousers from the 1800s are made of wool twill.

The twill you’re probably most familiar with is denim. Jeans are made from denim, a particular kind of cotton twill made with a white warp and an indigo (dark blue) weft.

Satin

Satin is the most complex of the basic weaves. It uses at least five harnesses, as the weft in a satin fabric goes over one warp thread and at four least four (or more) warp threads in an irregular pattern. Like a twill, it skips over warp threads, but it doesn’t make the diagonal line that twill is known for, because the skips are staggered. This leads to a smooth fabric with many threads packed tightly together and satin’s distinctive shine.

The word 'satin' as we have described it refers to the structure of the fabric, not any one kind of cloth. A satin pattern can be woven in any fiber, but some say that true satin can only be made of silk. A satin weave in a fiber other than silk-- usually cotton, rayon, or synthetic fibers meant to imitate the look and feel of silk-- is sometimes called 'sateen'. Sateen can also refer to the underside, or reverse, of satin.