What is the difference between a woven fabric and a knit fabric?
I often hear this question from sewists when they first start out and it's an answer that requires some diagrams to help explain.
When a fabric store describes a fabric as a woven or a knit, they are referring to how the fabric is constructed.
WOVENS
A woven fabric is woven on a loom. It has warp threads that run from top to bottom and weft threads that run from side to side. The warp and weft threads on the outer edges form the selvedges which run the entire length of the fabric panel.
Take a look at how a handwoven yarn dyed ikat fabric is created on a small scale hand operated loom here. The warp threads are creating a structure for the weft thread (wrapped around a shuttle) which is passed back and forth across the warp threads as they are moved vertically up and down each time the shuttle moves through the middle of the loom.
The weaver continuously checks the tension of the thread and pushes each row of the weft threads firmly against the previous row as they operate the loom. As you can see, it's alot of work which requires hundreds of hours, great skill and patience.
Here's a short clip of a flatwoven rug being made by a team of weavers on a much larger loom
Industrial production of fabric uses the same concept but on a much larger scale using machine looms.
There are many kinds of weave that use the warp and weft threads in various patterns to create different effects which, in turn change the drape and appearance of the fabric.
For example: satin, twill, canvas, herringbone, basketweave and plain are all types of weave and some of these words are also used as the names for the type of fabric when sold in retail stores...however, there are many more fabric names which will fall into one of these types of weave category.
Poplin, Quilting Cotton and Canvas are all plain weave fabrics where the warp and weft threads are evenly woven in a 1:1 ratio like in the example below
This creates a strong fabric with an even and usually 'crisp' drape which is easy to sew and often very beginner friendly.
Satin, Sateen, and Charmeuse are all satin weave fabrics where a number of weft threads are woven over multiple warp threads in a different ratio (sometimes 1:3 or even up to 1:16) so that there is a surface sheen created by the floating warp threads.
In this example, the warp yarns are shown running top to bottom, weft running sideways folding at each side. In this case, each warp thread floats over 16 weft threads, then passes under one weft thread, then floats for 16 more threads.
You would need a microscope to zoom right on to see the way the threads are laying against each other on a satin weave fabric because the individual yarns are usually very fine in these types of fabrics. The satin weave looks and feels luxurious with a softer hand or drape but is somewhat more delicate and less durable than a plain weave. Satin weave fabrics are much more prone to snagging than most other fabrics.
Cotton Sateen is great for dress making and I often use it for sewing cot sheets and wholecloth quilts as the delicate sheen and fine weave makes my prints really stand out. The Organic Cotton Sateens available in my shop are all 100% GOTS organic cotton. (GOTS stands for Global Organic Textile Standard)
Twill weave fabrics like drill and denim are woven with a diagonal appearance to the weft threads which is particularly noticeable on denim thanks to the way the fabric is dyed. Note the weft threads in the example below do not run diagonally but the way they are woven creates a diagonal pattern.
Twill weaves are usually strong, tend to be less prone to fraying and typically have a uniform finely striped surface appearance. Depending on the threads that make up the fabric, the twill may be completely matte (no shine) or have a subtle sheen from polished cotton threads or a glossier fiber content (like in some Tencel twills)
Twill weaves are usually an excellent choice for woven pants, jumpsuits, overalls, jackets and coats.
Some fabrics are woven from specially textured or twisted yarn or thread. For example, Georgette, which was originally made from silk but is now often made from polyester, is made with highly twisted yarns. The characteristic crinkly surface is created by alternating S- and Z-twist yarns in both warp and weft. Georgette is a very fine lightweight crepe fabric. There are historically many kinds of crepe fabrics, made with twisted yarns to create uniquely textured and wrinkled fabrics. See a long list of Crêpes here. There is now a Crepe fabric available in my shop, printed by Next State Print in Australia.
Always check the fabric weight and the recommendations on the pattern for the fabric type and fabric weight range the pattern is designed for. Bear in mind, you can sew any pattern in any fabric you like... it just might not work out the way you expect! When a pattern company sews a range of samples to demonstrate a pattern, they (or their pattern testers) will usually try various types of fabrics and share pictures of how the pattern looks when sewn up in these fabrics. When starting out, it's a good idea to use a similar fabric to those used by the pattern designer in their sample photos as this is more likely to give you a similar result in drape and garment fit.
If they have designed a pattern with heavy cotton drill in mind, then using a mid weight basic cotton or linen fabric will probably result in a looser, more casual or drapier looking garment than intended for the design... but it's not wrong to use a different fabric, if you like the result.
Some patterns can be 'fabric chameleons' and can be sewn in either woven or knit fabrics... but this is getting ahead of ourselves. First, let's find out 'What is a Knit fabric?'
KNITS
Knit fabrics are... well, knitted! And no, not on your grandma's knitting needles (though that is a smaller scale way of creating a knit fabric) in fabric manufacturing, a knit fabric mill uses various kinds of knitting machines and continuous spools of yarn to create fabrics made of many interlocking loops (often very tiny loops) to create knit fabrics with a little or lots of stretch.
Where does the stretch come from?
Because knit fabric is made from loops of yarn instead of a flat weave, the fabric construction inherently provides some stretch, but not ALL the stretch. Stretch also comes from the types of yarn and fiber content used in the knit. Many knit fabrics will have some elastic content in the form of 'elastane' 'spandex' or 'lycra' which are all brand names for the same thing: elastic yarn. Many knit fabrics also have another fiber blended with the elastic yarn, usually cotton or polyester, sometimes nylon, viscose or rayon, even linen can sometimes be used in a knit fabric, though be aware that some fibers are better suited to being stretched again and again than others. Some methods of knit construction provide greater stretch than others.
You may see terms like warp knit or weft knit used to describe some fabrics. Here are examples of each.
Fiber Content
Polyester, nylon and lycra/spandex blend fabrics are very commonly used in ready to wear athletic garments because they can be stretched over and over and bounce back into shape, they are considered a durable knit fabric and can often have a very high stretch percentage.
100% cotton knits can be fairly stable knit fabrics with very little stretch and usually little stretch recovery. Because there's no elastic yarn to pull the cotton yarn back into shape, once it's stretched out, it will probably stay that way.
Fleece, Minky and french terry are all types of knit fabrics that have some 'give' in the fabric, but may not necessarily have much stretch recovery (if any) unless they also contain an elastic yarn in their construction (it is rare to find these fabrics blended with elastane or spandex). The way these fabrics are knitted, with surface or reverse side loops, creates their unique characteristics and texture. Next time you pick up your bath towel, take a closer look at the fabric construction - is it a knit or a woven? Most fluffy bath towels are in fact a bulkier version of a terry fabric with long fluffy loops of thread on a knitted base.
Stretch Recovery
Stretch recovery refers to how much you can stretch a fabric and then have it bounce back into it's original shape. If you have noticed the way your track pants go baggy in the knees, that's due to a lower stretch recovery in the knit fabric used to make those track pants.
So how much stretch percentage do you need?
This will depend on the pattern.
Knits vary in their construction, stretch percentage, weight, stretch recovery and fiber content just as much as woven fabrics vary. An important thing to note in any sewing pattern is whether there is a guide to the minimum or maximum amount of stretch a fabric should have in order for the pattern to work the way it should.
This is particularly important for close fitting garments like leggings and athletic wear. Check your pattern instructions for a chart that might look something like this:
To test the fabric and determine stretch percentage on a ruler or tape measure, grab your fabric and fold a little edge you can hold up to the ruler. You can mark 2 notches 10cm apart on the edge of the fabric or just hold the fabric with your fingers placed 10cm apart on the folded edge of the fabric crossgrain (crossgrain = across the fabric width from selvedge to selvedge, not along the selvedge edge)
Line up one marker at 0 on the ruler, and the other marker at 10cm, then pull the 10cm marker as far to the right as you can. You will be able to feel when the fabric can stretch no more. Note where on the ruler it stops stretching.
For example: If you can stretch the fabric to 17cm, there is 70% stretch in that fabric.
If you can stretch the fabric only 1cm to the 11cm mark on the ruler, there is only 10% stretch in that fabric. In the example above, the fabric stretched to 12.5cm which means it has 25% crossgrain stretch.
You can see on the imperial side of the ruler that the 4 inches of fabric stretched to 5 inches which equals 25% stretch. If 4 inches stretches to 6 = 50% stretch, stretching to 7 = 75% stretch, stretching to 8 = 100% stretch...
There's a formula for this if you happen to be working in inches or are testing a smaller or larger piece of fabric for some reason, but the 10cm sample method is the easiest way to skip the math.
Further Resources, Reading & Listening
I highly recommend further reading and listening via Episode 27 of the Love to sew Podcast: Fabrics 101
And take a look at the Choosing Materials info on my website where examples of all the types of fabric my designs can currently be printed on. There are close up photo examples which you may find very useful. You can also order swatch booklets or sample packs from any of the printers I typically use to print my designs for me:
The fabrics mentioned in this blog post are just a few of the many different types of fabrics available to the home sewist. There are many more types of woven and knit fabrics I did not mention above so if you have specific questions about a type of fabric or have any helpful fabric info to share, please leave a comment below.
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