Have you ever found yourself cutting out a new pattern, only to find that the resulting garment you sew doesn’t fit properly when using stretchy fabric? Fabric elasticity is a factor that many sewists don’t consider when they’re creating a pattern, but it’s a huge factor that decides how your garment will look.
What is fabric elasticity? This term refers to how stretchy your fabric is, and it is calculated by a percentage. A type of fabric can have a two-way stretch or a four-way stretch, and knowing the direction of the stretch and the stretch percentage will help you make the best final garment.
This article will provide a complete guide on fabric elasticity and how it affects the final results of your patterns. You will also find some common types of stretchy fabric for your next garment below.
What Makes Fabric Stretchy?
A type of fabric can be stretchy because of two factors: its construction or its elastic fiber content (for example, a spandex blend is stretchy because spandex is a stretchy fiber).
There are also different types of stretchiness: two-way stretch or four-way stretch. A piece of fabric has a two-way stretch when it’s only stretchy in one direction (either horizontally or vertically), while a piece of fabric with a four-way stretch is stretchy in all directions.
First, let’s talk about fabric construction. This is how the fibers are connected to constructed to create a piece of fabric. There are two main types of fabric construction: woven and knit.
Woven fabrics are constructed with warp and weft threads that are crisscrossed over and under one another to create a solid piece of fabric.
As a result of this construction, woven fabrics usually do not have a lot of horizontal or vertical stretch. That is, when you pull the fabric in the same direction as the threads, the amount of stretch is minimal.
However, when you pull against the grain of the fabric, which means pulling the fabric diagonally, you’ll see some stretch. This is called the bias grain, and sewists usually use a technique called bias cutting to cut along the bias grain to add stretch to a piece of non-stretchy woven fabric.
A knit fabric has a series of interlocking loops that are connected in stitches. Each row contains a series of stitches constructed from one long, continuous thread. As a result of this construction, knit fabrics usually have excellent horizontal stretch but not much vertical stretch.
Besides construction, a type of fabric can also be stretchy because of its fiber content. Many types of fiber are naturally stretchy, including spandex, lycra, or elastane.
When these types of fibers are in the fiber content, the fabric can become quite stretchy, and it is usually a four-way stretch. This stretchiness is regardless of the construction, so a woven cotton-spandex blend fabric can be stretchy because of its fiber content and not its construction.
If a fabric is not stretchy, you can also add stretch to the fabric using a special sewing technique called shirring. This is where you use elastic threads, rather than regular threads, to sew multiple lines across the fabric’s length to add horizontal stretch to it.
This technique is often used to add a functional as well as aesthetic touch to a design. However, shirring is different from the other types of stretch because it is often added when you sew the garment rather than being a part of the fabric itself.
Why You Should Know About Fabric Elasticity
Why does it matter to know about fabric elasticity anyway? Well, this factor is particularly important when you want to make a tight-fitting garment.
When you use the stretchy fabric, you’ll expect that the final garment can expand to hug your body, but that also means your body’s measurements won’t match up to what you need to cut out from the fabric.
Knowing how much you can expect the fabric will stretch will help you determine the size that you’ll need to cut out to create the perfect garment that fits.
What if you’re using a pattern? How do you determine if the fabric you’re using has the right elasticity that the pattern calls for? We’ll cover how to calculate fabric elasticity in the next section.
Don’t worry if your fabric elasticity doesn’t match up to the pattern’s requirements. If you are using a less stretchy fabric than the pattern’s required elasticity, simply go up a size or two to account for the fabric’s low elasticity.
Similarly, if you are using a very stretchy fabric that’s much stretchier than the pattern’s requirements, you can move a size down. The stretchy fabric will make up for the smaller size, and the garment will fit perfectly.
How Is Fabric Elasticity Calculated?
In this section, we’ll have to use a bit of math to calculate a piece of fabric’s elasticity. It’s not very complicated, but it’s going to be very helpful when you are determining whether a piece of fabric is suitable for a certain pattern.
The elasticity of a fabric is the result of stretching it to the maximum without causing it to be deformed. It can be measured in various ways, such as horizontally, vertically, or across the bias of the fabric.
A fabric’s bounce is the capacity it has to recover its original measurements after being stretched. If the fabric stretches but does not bounce back, it’s not going to maintain its shape after one or two washes.
You’ll also hear the term double-bounce when referring to stretchy fabric. This means that the fabric can bounce back when stretched both vertically and horizontally.
To calculate the elasticity percentage of a piece of fabric, you’ll need to know two measurements:
- The length of the fabric when completely relaxed
- The length of the fabric when completely stretched yet able to bounce back without being deformed
You can easily measure these two measurements using your piece of fabric and a tape measure. When you have the measurements, the elasticity percentage is calculated as:
X % = (b – a)/a x 100
For example, let’s say you have a piece of fabric that’s 10 inches but can stretch out to be 12 inches without being deformed. The elasticity percentage will be:
(12 – 10)/10 x 100 = 20%
How is this number helpful? You’ll have to subtract the stretch percentage from the actual measurements so that the garment will fit you well because the fabric will stretch out to make up for the difference.
Let’s say you are making a tube top with this fabric, and your bust measures 36 inches. Accounting for 20% stretchiness, you’ll only need to cut out a length that’s 36 inches x (100% – 20%), which is 28.8 inches. The 28.9-inch piece of fabric will stretch out to reach 36 inches and hug your body comfortably.
Keep in mind that stretchiness can be measured vertically, horizontally, or diagonally (along the bias grain). If you have a four-way stretch fabric, the calculations will need to be applied to all of the measurements of the pattern to get the most well-fitting garment.
Types Of Stretchy Fabrics
As we’ve mentioned, a fabric can be stretchy because of its knit construction or its fiber content that contains naturally stretchy fiber.
There are hundreds of types of stretchy fabrics, so we won’t mention all of them here, but below are some popular types of stretchy fabrics.
|Type Of Fabric||Stretch Direction||Type Of Stretch|
|Knit fabric||Two-way||Knit construction|
|French Terry Cloth||Two-way||Knit construction|
|Spandex/spandex blend||Four-way||Fiber content|
|Nylon/nylon blend||Four-way||Fiber content|
1. Knit fabric
Any type of fabric that has a knitted construction can have two-way stretch. This refers to both hand-knitted items as well as machine-knitted fabrics that you can find in the fabric store.
What gives the fabric its stretch is the knitted construction, so it doesn’t matter what the fiber content is; the fabric will be stretchy, whether it’s wool, cotton, acrylic, or something else.
However, the style of knitting will decide the elasticity percentage. Rib knits are much stretchier than fabrics with plain purl or knit stitches. Cable knits also tend to be stretchier than plain stitches.
Jersey knit is another popular type of stretchy knit fabric. It’s soft and slightly stretchy, making it ideal for both summer and winter clothing.
Most jersey knit fabrics are made from cotton, which is very lightweight and breathable. Nowadays, you can also find jersey knit made from polyester, which is more affordable and has superior moisture-wicking abilities but is less breathable than cotton.
Polyester jersey knit is often used in sportswear because it’s lightweight and dries faster than other types of fibers. This is also why a sports team’s uniform is often called a jersey.
Regardless of the fiber content, the two-way stretch of jersey knit is created by its knitted construction. Because the knit construction is created by a machine rather than by hand, the stitches are very, very tiny, and the amount of stretch depends on the size of the stitches.
Jersey knit is also referred to as a single-knit fabric, which means that there’s a right side and a wrong side to the fabric. In contrast, double-knit fabric looks the same on both sides.
3. French Terry Cloth
Like jersey, French terry is a single-knit fabric that has a series of soft piles of yarn on one side and a smooth knitted surface on the other. Because of the knit construction, this type of fabric is also quite stretchy and comfortable to wear.
Thanks to the piled side, the fabric is also incredibly soft and comfortable to wear, which is why it’s most often used in loungewear, hoodies, and sweatpants.
Depending on the fiber content, you may also enjoy other benefits of the fibers. For example, a cotton or cotton-blend French terry is soft, lightweight, and breathable but can still retain heat very well.
Polyester French terry is also very soft, but it’s a bit less breathable than cotton, so it can feel stuffy during the summer. Polyester French terry is more suitable in a cooler climate because this type of fiber can trap heat very well to keep you warm.
Mesh is an intriguing case where a woven fabric has a four-way stretch, and this is thanks to its very loosely-woven construction that results in thousands of very tiny holes across the surface of the fabric. This construction is what gives mesh its stretchiness.
Mesh can be made from various types of synthetic fibers, including polyester and nylon. Thanks to the loosely-woven construction, mesh is also very breathable, which cannot be said for other types of synthetic fabrics.
Because of the fabric’s stretchiness and breathability, mesh is often used in workout clothes, lingerie, shapewear, and even shoes and accessories.
5. Spandex / Spandex Blend
Spandex (also called lycra or elastane) is a unique synthetic fabric that’s known for its superior elasticity. A piece of 100% spandex fabric can stretch five to eight times its original size and bounce back without losing its shape!
Although spandex has revolutionized the production of various types of clothing, 100% spandex is very rare, mainly because nobody needs to have that kind of stretch in their clothing and also because spandex can be quite uncomfortable to wear.
Spandex is not very breathable; it can stick to your body and trap moisture and odor inside. That’s why spandex is often blended with other fibers like cotton, rayon, or polyester, and you don’t really need much spandex content to enjoy the fiber’s stretchiness.
Manufacturers use a small amount of the material in combination with other materials to add elasticity to a non-stretch fabric. A spandex blend can look like 95% cotton/rayon/polyester and 5% spandex, and this blended fabric can already stretch 10 – 20%.
A cotton-spandex blend, like stretch cotton poplin, can be very stretchy while enjoying the benefits of cotton: soft and kind to the skin, breathable, moisture-absorbant, among other benefits.
A polyester-spandex blend is very suitable for sportswear because it’s stretchy and hugs your body comfortably. Polyester is also lightweight and has superior moisture-wicking abilities, keeping you warm throughout your workout.
A rayon-spandex blend is also great for everyday wear. Rayon is known to be an affordable, semi-synthetic alternative to silk. It’s lightweight, silky smooth, and very breathable. Adding only 3% of spandex to the fiber can add stretchiness and make it more comfortable to wear.
6. Nylon / Nylon Blend
The name ‘nylon’ can remind you of plastic, and while this material is also made from chemicals derived from petroleum, it doesn’t necessarily feel plastic-like.
Instead, nylon is a very flexible and silky fabric that has superb elasticity. It’s been used to make women’s pantyhose since the 1940s thanks to its superior strength and ability to be stretched out very thin without breaking or losing its shape.
Nylon is also an incredibly resilient fabric. It is abrasion-resistant and can easily be laundered, which is surprising considering its silky-smooth appearance.
However, similar to spandex, you’ll hardly find 100% nylon anywhere. Similar to other types of synthetic fabrics, it’s not very breathable. When it’s hugging your body, it also doesn’t do a very good job of wicking away moisture.
This is why nylon is also often used as a blended fiber to add stretch to other non-stretch fibers, like cotton or polyester. You’ll find nylon content in your yoga pants, swimsuit, tights, and stockings – garments that need to hug your body well.