How to Cut Stretch Knit Fabric

Stretchy knit fabrics such as jersey, sweatshirt fleece, and sweater knits behave differently to woven materials, so they need a little more care when it comes to cutting out your sewing project.

In this post, I’ll share my best tips for prewashing stretch knit fabric, finding the straight grain, and cutting pieces accurately without stretching the fabric out of shape.

How to prewash knit fabric for cutting

Before you start cutting out for your fabric, it’s important to prepare it correctly to avoid shrinkage, dimpling and distortion.

1. Prewash and dry your fabric

Even though it's stretchy, knit fabric can shrink just as much, or even more, than woven fabrics when it's washed. Ask me how I know! So it’s important to get any shrinkage out of the way before you cut out your pieces, to avoid ending up with a garment that's too small after its first wash. 

Wash them on the same settings you plan to wash your finished garment, following any care instructions for the type of fabric you’re using. Tumble drying stretch knit fabrics can be risky, so use a low heat and gentle cycle, and test on a swatch first. To air dry your material, lay your fabric as flat as possible, avoiding hanging it over any corners or prongs on a drying rack which can over-stretch the material and cause dimpling.

2. Press your fabric if needed

Knits tend not to crease as much as some woven fabrics, but you may still need to give yours a quick press, particularly if it has a crease line where it was folded on the bolt. 

Always test your iron settings on a corner of the fabric first to check the temperature isn’t too high, and keep pressing to a minimum to avoid stretching out the material.

3. Let your fabric rest

Washing your fabric, hanging it up to dry, and dangling it off the ironing board while pressing it all have the potential to stretch the material so, if you can muster the patience, give it the opportunity to relax before you cut it out. 

Lay it flat or folded on a table for a couple of hours so it can settle back into shape before you start cutting into it.

How to lay out knit fabric for cutting

When you’re ready to cut out your fabric, lay it out on a large table protected with a large cutting mat.

1. Find the straight grain

When laying out pattern pieces on fabric, it’s important to align the grainline arrows on the pattern with the straight or lengthwise grain of the fabric. This ensures that the garment hangs correctly and has sufficient stretch to fit as intended.

On woven fabrics, the lengthwise grain is usually parallel to the selvedges, or finished edges. On stretch knit fabrics, these edges can be less obvious – sometimes they’ll have little glue dots along them, or they may have simply been cut.

Instead, the lengthwise grain can usually be identified as the direction with the least amount of stretch, so give it a pull. If you look closely, you may also be able to see vertical ribs running down the lengthwise grain on the right side of the fabric.

2. Fold the fabric along the straight grain

Once you’ve identified the straight grain, you can fold your fabric lengthwise along it. When folding woven fabric lengthwise, you can usually simply bring the selvedges together – but on knit fabrics, the edges often don’t exactly align with the straight grain.

To ensure the fold is in line with the straight grain, hold up the fabric along the edges and adjust the fold until it hangs without twisting.

Alternatively, if you can see the vertical ribs running down the length of your fabric (look closely!), fold your fabric in line with one of them.

This will help your finished garment hang nicely without twisting.

3. Create multiple folds if appropriate

Many knit garments don’t have any fastenings, as the stretch allows them to be pulled on and off easily. For this reason, it’s common for both the front and back pattern pieces to be cut on the fold, with no centre openings.

If your fabric is wide enough, you can often save material by creating two lengthwise folds to lay out your pattern pieces, folding both edges towards the centre. Check the cutting layout diagrams for the pattern you are making.

In fact, some knit fabrics come in a tubular shape, meaning they already have two folds. You can leave them as they are to use both folds – this can be particularly helpful for ribbed openings such as neckbands and cuffs – or cut the fabric open along one of the folds if needed.

4. Consider cutting on a single layer of fabric

Folding fabric before cutting out your pattern allows you to cut two layers at once, resulting in either a matching pair of sleeves, for example, or a symmetrical piece such as a bodice when placed on the fold. However, the under layer can sometimes shift off grain if your fabric is particularly stretchy or slippery.

To be extra certain that you are cutting both pieces or sides on grain, you might want to cut on a single layer of fabric so you can check the grainline arrow is still aligned with the vertical ribs. For pattern pieces with a “place on fold” line, trace off a full-sized symmetrical piece first. For pattern pieces to be cut as a symmetrical pair, cut one with the pattern face up, and one face down.

5. Don’t let the fabric hang off the table

If your fabric is too long for your cutting table, fold or roll the end up so it doesn't hang off the edge and stretch the fabric out of shape. You may need to cut a few pieces at a time.

Smooth out any wrinkles or ripples in the fabric that is laid out flat, checking both layers if it is folded in two.

How to lay out your sewing pattern on knit fabric

Cut out the pattern pieces in your size, and lay them out on the fabric. The cutting layout diagrams that came with your pattern will suggest an economical way of positioning them on the fabric – however, bear in mind that they can’t account for every size and fabric width, so you may find a better way.

The lengthwise edges of stretch knit fabrics can sometimes be distorted. If you notice they are running at a diagonal angle, try to avoid placing the pattern pieces close to the edge to avoid twisting.

As with woven fabrics, it’s important to align the grainline arrows on the pattern with the straight grain of the fabric to ensure your garment fits as intended and hangs without twisting. Take the time to check the grainline arrow is exactly lined up with the vertical ribs in the fabric. When cutting sleeves, for example, I like to fold the pattern piece along the grainline arrow, align this fold with a rib, then carefully position the rest of the pattern in place. 

You can use pins to secure your pattern pieces in place. However, pins can stretch out your fabric resulting in less accurately shaped pieces. If you plan to cut with a rotary cutter (more on that below), consider using weights instead of pins to hold the pattern pieces in place. You can buy dedicated pattern weights, or use large washers from a hardware store, or anything flat and heavy that you have to hand. I often grab a few cookbooks for this purpose!

If you do use pins, try to get ballpoint pins, which won’t snag the looped structure of the material. If you only have regular pins, position them within the seam allowance to avoid accidentally piercing any holes in your garment.

Read tips for cutting and sewing with stripes

How to cut knit fabric accurately

You can cut knit fabric with regular fabric scissors, however the lower blade will lift up the fabric as you cut, potentially stretching it out and leading to inaccurate shapes. If you do use scissors, use long strokes, and try not to stretch the fabric as you cut.

A rotary cutter will give you a more accurate result. This tool, which is similar to a pizza cutter, rolls a circular blade along the fabric, meaning it can stay flat on the table during the process.

Simply roll it firmly along the outlines of your pattern to cut the fabric. Rotary cutters are very sharp, so be sure to use a cutting mat to protect your table. To protect yourself from nicks, keep your fingers away from the blade, and remember to cover the blade each time you put it down.

How to mark knit fabric

Once you’ve cut out your pieces, remember to add any pattern markings to the fabric. Use regular fabric scissors to cut short snips for the notches – about 5mm (1/4in) – at right angles to the fabric edge. If you need to transfer any other markings to the fabric, use a removable marker such as chalk pencil or iron-erasable or washable pen, checking it comes out of the fabric first.

Identifying the right side of the fabric

Your pattern instructions should tell you whether to add any markings such as darts, pleats or pivot points to the right or wrong side of the fabric. The right side will show on the outside of the garment, the wrong side on the inside. 

On some knit fabrics, it’s obvious which side is which – the right side may have a print, or the wrong side may have a soft, fleecey texture. On others, it can be less obvious – in which case, take a closer look. You may be able to see visible ribs formed of little Vs on the right side, and either horizontal loops or a fuzzy texture on the wrong side.

If you still can't tell which is which, don't worry too much about it!

Ready to sew knit fabric?

Once you've cut out your pieces, keep them flat until you’re ready to use them.

If you’d like some help learning to sew with stretch knit fabrics, check out my online workshops Learn to Sew Jersey Tops and Make Friends with an Overlocker or Serger, my book Stretch! Make Yourself Comfortable Sewing with Knit Fabrics, and our collection of sewing patterns for knits.