Tips For Sewing With Knit Fabric

Welcome to this sewing with knit fabric article where I share my experience from working with knits and the tips I’ve picked up along the way! Sewing with stretchy fabric (knits) takes practice, but once you get the hang of it, it can be really rewarding to end up with knit basics that you wear everyday. In this article I talk about what even is knit fabric, tools that will help you out when sewing with knits and tips for sewing with knits.

I have to admit, it took me a little time to start loving sewing with knits. I remember thinking “Oh I don’t want to start sewing my own t-shirts, I’ll just buy them” and after making the first one, I was hooked. There’s something really satisfying about sewing basics, like t-shirts, loungewear or even underwear to make you really appreciate the everyday clothes you wear.

Sewing up a tee or cozy sweatshirt can be a great palette cleanser between more involved projects (like sewing jeans). Even though sewing with knits is really different than sewing with woven fabric I’ve come to love it in its own way. And when I need a break from sewing with knits, I switch over to woven fabric and vice versa! 🙂

I’ve had plenty of knit sewing fails, I still struggle sometimes with my thread tension, and my twin needle and I don’t get along most of the time, but I’m here anyway to share what I’ve learned about sewing with knit fabric!

Be sure to check out my article where I’ve complied all of my favorite sewing patterns for knit fabric, most of which are shown in this article, for ideas of which pattern to start with.

I’ve added a Table of Contents so you can skip around to specific sections:

How To Get Started Sewing Knits?

My best advice is just to go for it and then practice…a lot! If you’re completely new to sewing with knits, then a t-shirt would be a great place to start! An oversized tee would be even better so you don’t have to worry too much about the fit. There are a lot of free t-shirt patterns out there like the Stellan Tee which was my first t-shirt pattern I made (pictured below).

Practice with inexpensive fabric – The first fabric I practiced on was from Walmart (shown above) which I ended up loving and found it easy to work with! From there you can move on to trying out different types of fabric to figure out what you prefer. One thing I really like about knit fabric is that is typically comes in wide widths like 58″-60″ (or sometimes more) so you can get more out of a smaller yardage.

What Is Knit Fabric?

Knit fabric is basically what it sounds like – fabric that has been knit together vs. woven fabric that has been…well, woven together. Knit fabric is made by looping together one continuous thread that create a “braided” look and give the fabric that stretchiness. If you look really closely you can see rows of “v’s” on the right side of the fabric. (This is really similar to the stockinette pattern in hand knitting, where the right side has the smooth knit pattern and the wrong side has the bumpy purl pattern.)

Stretch Recovery

Stretch recovery is how well knit fabric can go back to it’s original shape after being stretch. Knit fabric with high stretch recovery is usually made with spandex (elastane) and is great for fitted garments. Low recovery knit fabric, like 100% cotton or with low elastane, is better used for looser fit garments, like pullovers and sweaters.

For example, the Sommar Camisole by Paradise Patterns is designed for knit fabric with a high percentage of stretch and recovery – at least 50% stretch – and recommends fabric with an elastane (spandex) content.

A lot of trial and error went into finding a great fabric fit for the Sommar Camisole and I made several in different types of fabrics. None of these pictured below worked out for different reasons, like using fabric with too much rayon that made the fit too loose, using a 100% cotton or using a pointelle knit with low recovery, but I learned a lot throughout the process.

After many versions in different types of fabric, my favorite fabric for the Sommar Camisole has to be Valencia Organic Cotton Jersey from Lyrical Fabrics (shown below). It’s also my favorite for making underwear because of how soft and comfortable it is to wear!

Stretch Percentage

Stretch percentage is the amount of horizontal stretch that a knit fabric has when stretched from a fixed point. The amount of stretch percentage is important when picking out knit fabric for a project because most knit sewing patterns are designed for a certain stretch percentage range. Most fabric websites will let you know how much stretch percentage a fabric to help when pairing fabric to a sewing pattern.

If you’re using a mystery knit fabric, you can calculate the stretch percentage yourself! Here’s a helpful article by Megan Nielsen to show you how plus a downloadable stretch percentage guide.

You can also have a knit fabric with a high stretch percentage but low stretch recovery. For example, cotton pointelle knits have little to no spandex content, which gives it that low stretch recovery, but still have 60% stretch. The Honeygirl Tee by Paradise Patterns (or other patterns in the Honeygirl series) was specifically design for pointelle fabric. My review of the Honeygirl Tee goes into more detail about working with pointelle and I share all the versions I’ve made if you’re curious to give it a read.

All knit fabric stretches simply because of how it is made, but by also taking into consideration the stretch recovery and fiber content, you’ll get a better idea of how a knit fabric is going to perform as a garment.

Fabric Weight

Simply put, fabric weight is how light or heavy a fabric is, and usually measured in grams per square meter (GSM) or ounces per square yard (oz/yd²). So, the higher the number, the heavier the fabric will be and vice versa.

Fabric weight needs to be considered when choosing knit fabric for a garment since it can greatly affect the final fit. If you pick a lightweight knit for a low ease fitted camisole (like the Sommar Camisole I mentioned earlier) chances are you will need to size down to accommodate the extra ease.

For patterns designed with high ease and low stretch fabrics in mind, the weight can also make a difference in the final fit. For example, the Wren Fleece by Daughter Judy Patterns is designed for heavy weight sweatshirt fleece (or other knit fabric) at 11-14oz weight to help retain it’s oversized shape. If you go down in weight you may want to size down as well because a lighter weight fabric will give more ease and drape.

I’ve made the Wren Fleece several times and my favorite fabric to use is a 9oz cotton sweatshirt fleece from Lyrical Fabrics (below left picture). I’ve also made the Wren Fleece in a lighter weight sweatshirt fabric (I can’t find the weight info anymore!) which fits with more ease and drape (below right picture). It’s maybe a little hard to tell from the photos, but the gray sweatshirt doesn’t hold the shape as well and feels thinner and airier when wearing.

Fiber Content

Looking at the fabric’s fiber content will also give you a good idea of how the finished garment will fit. A cotton rayon blend is going to have more drape and be slippery to work with. A high cotton content will give more structure and is generally easier to work with. Linen or hemp cotton blends have great texture and feel amazing on the skin. And of course, any knit with spandex (elastane/lycra) is going to have better stretch recovery.

For the most part I try and pick knit fabric with more natural fibers in it – like cotton, linen, hemp – because I find they’re the easiest to work with and so comfortable to wear (pictured below, left to right: rayon/linen jersey, 100% cotton jersey, rayon jersey).

Can You Sew Knit Fabric Without A Serger (Overlocker)?

The short answer to this question is…yes! You can definitely sew knit clothing without a serger and you don’t need one. My first knit projects were sewn without a serger and most of knit patterns I’ve made include instructions for sewing on a standard machine. Most knit fabric doesn’t fray like woven fabric does, so you can leave the edges to curl in on themselves, or you can finish the edges with a zigzag stitch for a neater look.

Now, would I recommend a serger? Absolutely. There is something so satisfying about whipping up a t-shirt with my serger in under an hour. Sergers are designed to sew with knit fabric because they create seams that stretch with the fabric. You can also adjust the differential feed to help knit fabrics feed through the machine without distorting it (although, I’ve never had to adjust my differential feed).

I find I get much better stitch stretch and more consistent tension results using my serger and I rarely have to fiddle with settings. The cons? Sometimes you need a little more control, especially on neckbands, or patterns with more intricate style lines.

For example, the Viola Top by Forget Me Not Patterns was made entirely on my regular machine and is actually necessary for all those cool tucks and folds on the front of the shirt (see my version below). I remember being so nervous to make this top, but the instructions (written and video) were great and I learned a lot through this make.

A serger or overlock machine is not just for knit fabric by the way, I use mine for finishing the raw seams on projects made with woven fabric (like dresses and skirts). You of course can start sewing your own clothes without one, like I did, but it is great for giving your garments a professional finish.

In case you’re curious, the serger I use was found secondhand (thanks mom!) and is a vintage Bernina Bernette 234 – loud, but a solidly built machine (see photo below). A serger that I’ve seen recommended is the Brother 1034D Serger and according to reviews, it’s a great basic machine for beginners and is easy to thread.

Coverstitch Machine

Recently I’ve been hemming my knits with my coverstitch machine and I’ve been loving the professional looking finish! A coverstitch machine is a specialty machine and that’s basically all it does – hem knit garments with ideal stretch – sort of like a serger does with seams. It’s definitely not a need, but I have been enjoying learning how to use mine and admiring the neat hems it makes.

I use a Janome 900CPX CoverPro that was factory refurbished from Ken’s Sewing Center. I was able to order it online (it shipped from Florida to Texas with no issues) and it works like brand new machine. I haven’t had any major issues with mine and, after learning the basics of how it works, find it pretty straightforward to work with.

Here’s a great article from Seamwork on the benefits of a coverstitch machine if you need some convincing (it convinced me!).

This page contains some affiliate links to products and I may receive a small commission for purchases made through these links (at no extra cost to you).

Some Things You’ll Need

• Jersey/ball point needles – These have rounded points to help them pass between the fibers of the fabric not through the fibers to prevent snagging. These work for most cotton knit, cotton jersey, and sweatshirt fabric.
• Stretch needles – If you’re using fabric with a lot of lycra or spandex stretch needles are designed to move through the fabric without skipping stitches.
• Twin Needle (optional)
• Walking Foot (optional) – I use mine the most when sewing the hems because it feeds the fabric in evenly and reduces wavy hems.
• Fabric Scissors
• Rotary Blade & Cutting Mat (optional) – You can use just fabric scissors, but with slippery knit fabric a rotary cutter can be super helpful.
• All purpose thread – Polyester thread has better stretch than cotton.
• Pins – I use regular pins, but there are ballpoint pins designed for knit fabric to avoid damage to the fabric.
• Serger/Overlocker (optional) – This is a very common serger I see other sewists use.
• Coverstitch Machine (optional) – This is the one I use!

Prepping The Fabric

Prewash and dry your fabric like you plan on washing your finished garment. Machine washing and drying will pre-shrink the fabric so you don’t have to worry about your finished garment changing sizes on you.

Ironing your knit fabric before using gets rids of those wrinkles and gives you a smooth surface to work from. It can feel a little weird ironing knit fabric because it stretches all over the place, but I will just lightly stretch it out so it doesn’t get bunched up under the iron.

Make sure you have the right heat setting for the fabric you’re using. Rayon and spandex are synthetic fibers so the more there is of it in the fabric, the lower you may want the ironing heat. I iron cotton/blends (92% cotton 8% spandex) on the cotton setting with steam just fine, but when working with rayon I always turn the heat lower.

Cutting Out the Pattern

Using a rotary cutter and cutting mat can really make cutting out knit fabric easier, especially if it’s slippery knit, like rayon blends or especially swimwear fabric. Pattern weights will help keep your pattern and fabric in place. With thicker knits, like sweatshirt fleece or sweater knits, I find it easier to use fabric scissors for better control.

Make sure you’re paying attention to the grain! Knit fabric is different than woven fabric in that you can’t turn your pieces on the cross-grain. Instead you have to keep everything going the same direction and against the direction of greatest stretch (or DOGS). This is typically along the circumference of your body, where you want the great amount of stretch.

This is really important for neckbands, cuffs or waistbands where you want the most amount of stretch. When I made my first ever tank top, the Blomma Tank, I cut the neckband out wrong – going with the DOGS instead of against it – which is why the stripes are vertical vs. horizontal, and the neckband doesn’t lay totally flat (see photos below).

Pay attention to the grainline on the fabric and try to keep it going vertical especially when cutting on the fold. If the fabric is twisted when cutting, it can affect the finished look of the garment.

Tips For Sewing with Knits

Sewing with knits can definitely take some getting used to, and practicing on some scrap fabric can help you get a feel for it. It also helps to practice out stitch lengths and tension since everyone’s machines sew a little differently. I work with an older machine (that probably needs to be serviced soon) so I’m constantly fiddling with the tension, but you may not need to! Another reason why I prefer to use my serger when I can.

General Sewing Tips

• Don’t stretch the fabric as you’re sewing, let the machine guide the fabric through.
• Keep your project on the table as you sew and don’t let it hang down.
• Use the right needle for the right fabric and trying switching out for a new or different needle if you have skipped stitches.
• Pressing with an iron (at the right heat setting for your fabric) helps to set the seams and reduce stretching and waviness that may have occurred during sewing.

Stitch Length And Width

A zig-zag stitch is used when sewing with knits so that the fabric will stretch. Some pattern designers will recommend what stitch length and width to use and when in their patterns, but if not, here is a good place to start (you may need to adjust depending on how your machine handles knit fabric).

• Joining (narrow zig-zag) – 1-1.5 mm wide x 2-2.5mm long
• Basting – 1 mm wide x 4-5 mm long
• Finishing – 4-5 mm wide x 2 mm long
• Topstitching (straps, neckbands, hems) – 4 mm wide x 2.5 mm long
• Topstitching (hems, neckline) – 3 mm wide x 2 mm long

Of course, if you’re using a serger, then you are joining and finishing the seams at the same time. Most knit pattern seam allowances are 1/4″ (0.6 cm) and the default seam allowance for a serger is 1/4″ (0.6 cm) so you will line up your fabric along the edge of the foot – or at the red line on the foot, like on my serger. If the pattern has a larger seam allowance like 3/8″ (1 cm) or 1/2″ (1.3 cm) then, you will be cutting off the fabric as you sew. I use tape to mark larger seam allowances on my machine to use as a guide (see photo below).

A lightening bolt stitch can also be used in place of a narrow zig-zag stitch, which you may find works better on your machine/fabric (my machine doesn’t have one, so I can’t share my experience using it!).

I have heard that you can use a regular straight stitch on vertical seams although I have never tried it! I do use a straight stitch when topstitching my t-shirt or sweatshirt neckbands down and have never had an issue with stitches breaking (see photo below). However, when making the Sommar Camisole or Honeygirl Lounge Set, I use the recommend zig-zag stitch or a twin needle on the straps/binding since they need more stretch in those areas.

Needles

Universal Needle – Sometimes you can get away with using a universal needle since they are designed to switch between woven and knit fabric, but you may be better off using one of the needles designed specifically for knits listed below.

Ball point needle – A great go-to needle for most knits, like cotton jersey and sweatshirt fleece. These have rounded points to help them pass between the fibers of the fabric not through the fibers to prevent snagging. Also, make sure to match the needle size to your fabric – smaller needle size for lightweight and larger needle for midweight to heavyweight knit fabric.

Stretch needle – For knits with a higher spandex content, then you may want to try a stretch needle because they are designed to move through the fabric without skipping stitches. Stretch needles tend to give me the most consistent results so I usually use them instead of ball point needles.

Twin Needle – A twin needle can be used in place of a topstitching zig-zag stitch on hems and neckbands. To use a twin needle, two threads are used in the top along with the bobbin thread, and you sew with a straight stitch but the back is a zigzag to give stretch. Be sure to check your sewing machine manual for instructions on threading it and the recommended stitch length/width for your specific machine.

I love the finished look of a twin needle, but they can be tricky to sew with, especially depending on the type of knit fabric. I typically get better results with my twin needle when sewing on thicker or more structured knits, like sweatshirt fleece or cotton sweater knits.

When I try using a twin needle on slippery light weight knits, I find it hard to get the tension just right – if it’s too tight, then it causes “tunneling” and when it’s too loose, the bobbin thread slides around. You may want to adjust the bobbin tension if you’re having any of these issues (check your manual for how to do this on your specific machine). I suggest practicing first on scrap fabric to find the right balance of stitch length and tension.

Hemming

Honestly, I have a love/hate relationship with my twin needle and usually end up using a zigzag stitch on the hems even though I prefer the look of a twin needle. And sometimes leaving the hems raw so they curl up can be a cute option if you like that look!

If you have a serger, a great tip for getting a neater hem is to serge the edge first before folding and topstitching. Hems are only folded up once on knit garments and serging the edge first gives a little more structure for the stitches to sew through.

If you’re leaving the hems raw, I would suggest hiding the serger threads by hand stitching them inside the seam allowance (or you can also tie a knot with the thread tails before cutting). If you didn’t use a serger, then make sure to backstitch well to prevent the seams from coming undone.

If the hem is wavy after sewing, then pressing with an iron usually gets the rest of the waviness out (see photos below).

Tension

When sewing with knit fabric, you may need to adjust the tension for optimum stretch and neater stitch results. Tension settings can really depend on the type of knit fabric you’re sewing with and it’s always a good idea to practice on scrap fabric first.

Usually, you want to lower the tension for lighter weight knits or if there is a high spandex content to allow for better stretch. Start with a tension of 3 or 2.5 and go down from there if needed. For more stable knits, like 100% cotton jersey or thicker sweatshirt knits, a higher tension of around 3-4 is a good place to start.

If you’re using a serger, you may also need to adjust the tension depending on the fabric. I usually don’t have to adjust my tension (it’s set to 4 for all threads) unless I’m sewing with a pretty lightweight jersey, then I will lower the tension a little.

Walking Foot

A walking foot has extra feed dogs that, in combination with the machine’s feed dogs, help to feed the fabric through more evenly. This foot isn’t a necessity when sewing with knits, but it definitely helps in preventing wavy seams. I use mine the most on hems and when working with sweater knit or rib knit fabric with less stretch retention or more delicate knit fabrics (like the pointelle shown below).

Whew, if you made it this far, thanks for being here! This article sat in my drafts for a while and I’m happy I finally finished it. I would love to hear if you have any other great tips for sewing with knit fabric!

Happy sewing 🙂