Different Qualities of Knit Fabrics and How To Test Them {Video}

Welcome to the second lesson in the Beginner’s Guide to Sewing Knit Apparel! Download the ebook for free!

Now that you’re familiar with the different types of fabric available, there are some main qualities of knit fabrics you’ll need to become familiar with. These different qualities will determine the fit and look of your garment dramatically. So let’s blast through each of them really quick here!

Are you a video person? I have stretch, recovery, drape and structure covered in this quick video tutorial if you feel like reading is the pits 😉



There are two different ways that fabrics can be stretchy. Either they have a percentage of spandex content in them (also known as Lycra) or they have a mechanical stretch. Spandex is an actual stretchy material while mechanical stretch means the yarn is woven together in a way that gives it stretch.

Stretch is measured in percentages. Let me illustrate this. Let’s say a fabric has 50% stretch to it. That means 1″ of it will stretch out to 1.5″ (50% of it’s length). Knit sewing patterns will usually specify exactly what range of stretch percentage the pattern requires. This is an important fabric requirement you should never overlook. Using the too little stretch will usually produce a garment that won’t fit correctly.

You can measure your fabric stretch percentage in a split second by using this handy dandy stretch chart! Print it off at full scale on some cardstock and keep it close by for some easy stretch calculations.


Another aspect of fabric stretch is whether it is 2-way or 4-way. 4-way stretch means it stretches both up and down and side to side. 2-way stretch means it’s only stretchy in one of those directions, typically perpendicular to the grainline. Once again, most patterns will specify whether you will need 4-way or 2-way stretch.


A quality that’s discussed less often would be the stretch recovery of fabric. After the fabric has been stretched out, will it go back to it’s original shape? This is what you’re testing with fabric recovery. Fabrics with higher percentages of spandex or lycra will recover very well. Fabrics with more mechanical stretch to them, however, won’t recover as well. Fabrics without good recovery shouldn’t be used for patterns that are really tight. Over time they will start to sag and won’t fit the same as you intended.

Drape & Structure

The drape of a fabric refers to how well it falls over the body. Does it cascade over the shape of the body or does it fall more straight down giving the garment a more structured feel? Understanding drape and structure is important because it completely changes the look of the finished product.

For example, sweatshirts made with materials that lack good drape, will make you look boxy. However, sweatshirts made with fabrics that have good drape will have a slouchy/comfy quality to them. On the opposite side, a tight dress made with a fabric with too much drape may cling to the soft spots on your body you may be trying to camouflage a bit. A more structured fabric in that circumstance would give you the smooth silhouette you are looking for.


The weight of fabric is typically measured in the unit GSM. This stands for grams per square meter. A higher number means a heavier fabric. A heavier fabric means a thicker fabric. It’s difficult for me to give you direct fabric weight recommendations because it really depends on the project you are needing it for and your personal preference for the feeling of your fabric. When making your first fabric purchases, pay attention to the fabric weight so you can compare them to one another and start to get a feel for what weights you prefer.

Tip: My preferred weight for DIY LuLaRoe leggings, is 200 gsm double brushed polyester spandex

Your assignment for this lesson: Go back to the fabric shop or raid your own knit fabric stash and put them to the test. Figure out the stretch percentage for at least two fabrics by downloading and using the stretch percentage chart and test the recovery and drape of a few others too. Also, compare the weights of two different knits that are the same fabric type and think about how you would use them differently.

Look at you! You’re becoming a master of knit fabrics! Now that you are familiar with the different knit fabrics and their qualities, let’s start talking about sewing. Continue on in The Beginner’s Guide to Sewing Knit Apparel, by checking out the following lesson, The Best Stretch Stitches on Your Sewing Machine.

Editor’s Note: Enjoy this useful knowledge? Try it on the Althea Racerback Tank!


Originally Authored by Jessica Hooley. Archived by Kathryn Graham

Back to blog