Tips

Tips for sewing knits

We all love wearing stretch knit garments. They’re often more comfortable than ones made with woven fabrics, are very functional and practical. They don’t require ironing and are easy to care for. But not all sewers enjoy sewing knits. Do you find knit fabrics tricky to sew? Sometimes they stretch too much? Or perhaps you’ve never worked with them before? Keep reading, I can help! 🙂 

Choose the right fabric 

 If you don’t know what stretch fabric to use, try to stick to the knit types suggested in the pattern. Not all knits are the same. Although they all stretch, they don’t stretch to the same degree and in the same direction. 

Two-way stretch knits stretch only horizontally, across the fabric width.
Four-way knit fabrics stretch horizontally and vertically. Sportswear and swimwear require fabric that accommodates intensive physical activities therefore you would usually use four-way stretch for these. 

Some knits have more stretch, drape and weight than others. This is very important when choosing the fabric for your garment. For example, when working with a pattern designed for very stretchy fabrics if you used minimal stretch knit the garment simply wouldn’t fit! 

To determine how stretchy your fabric is cut a piece of the fabric and stretch it against the tape measure.  
For example, if you managed to stretch your piece from 10cm to 15cm that means it has moderate stretch (approx. 50%).  
Fabrics that stretch to approx. 25% have minimal stretch
Fabrics that stretch to approx. 75% are considered very stretchy

Look at the comparison of few knit fabric types that are commonly used within the industry in the table below. 

Type Stretch direction Stretch capacity Weight 
Jersey Two-way or four-way Minimal to very stretchy Light to medium  
French Terry Four-way  Minimal to moderate Medium 
Ponte Roma Two-way Minimal Medium to heavy 
Fleece Two-way Minimal Medium to heavy 
Swimwear fabric Four-way Very stretchy Heavy 

Stabilise your knit fabric before sewing

You don’t want to stretch your fabrics while sewing. That causes lettuce hems and overly stretched fabric. There are few methods of preventing knit fabrics from stretching. 

You can use tacking (basting) stitch and sew around the edges of pieces by hand. That would stabilise them, the thread would stop the fabric from stretching. This however can be a very time-consuming method, especially if your pattern has got quite a few pieces. Therefore, you could try something else: starch spray

Simply spray your fabric with the starch spray, wait until it dries a little and press with an iron. Don’t drag your iron across the fabric, only press. You will notice that your fabric got stiffer and not as stretchy. You might also see white marks from the white starch. This is only temporary. Fabric will return to its original state after rinsing or washing. 

You can buy ready-made starch spray in the aerosol but I prefer to make my own.

My recipe for starch spray: 

Mix half of the glass of COLD water with 1tsp of corn starch (or equivalent). Mix it well and pour it into a spray bottle. You can use it for a few days but after that, you will have to discard it.  

Tip: If you want to extend its shelf life simply add 50ml of vodka to the mixture but be careful, alcohol can ruin fabrics like acetate or acrylic fibres. I recommend trying it first on a scrap. 

You can also use clear elastic (framilon) for stabilising for example shoulder seams. I already mentioned it in this post.

Use the right equipment 

Threads

There are three types of threads that I use. There are pros and cons of using each one. 
 
The first one is the regular sewing thread.
Choose polyester over cotton one as it gives a little. It can be used for top thread, in the bobbin, in the overlocker loopers. It’s most versatile and comes in various colours and weights. It’s the same thread that we use for woven fabrics so there’s no need to buy additional spools and it’s not expensive. Unfortunately, you will have to select only stretch stitches on your sewing machine or use an overlocker to prevent it from breaking. 

The second thread type is woolly nylon thread.
This thread can be used in bobbins and overlocker loopers but it’s not suitable for the needle. It creates a very soft finish to the edges when used with an overlocker and it has a little bit of stretch. Try using it on the sample of your knit fabric, experiment with your machine tensions and select a long but narrow zigzag (wonky straight stitch) for topstitching. You might have to adjust bobbin tension slightly when using this thread for a balanced stitch. 

The third thread that I use is the Gutermann Maraflex thread.
I absolutely love the idea of having a thread that looks just like a normal thread but with the stretch. You can use it for everything. Topstitching T-shirts necklines, hemming. Sadly, it doesn’t come in as many colours, only sold in large cones and it’s not very cheap. 

Needles

You need special needles for sewing with knit fabrics: Ballpoint needles.
The ball point at the end of the needle displaces threads and goes in between the spaces.
Twin needles are very handy. Use them for hemming and topstitching for a neat finish. If you use an overlocker carefully read your instruction and use the right needles for your overlocker. 

Stitch selection

Be very careful when selecting your stitch type on your machine. Generally, use stretch stitches like zigzag or lightning bolt but a straight stitch isn’t necessarily a big no.
Check this post for my tips on sewing knits with straight stitch 🙂 

Last ingredient

And the last tip but most important one: enjoy your sewing! It’s a journey where you improve your skills over time challenging yourself to new fabrics, styles and techniques. Don’t get discouraged after making a garment that doesn’t fit as well as you’d like. We’ve all been there 😊 Happy sewing!