How & Why You Should Do A Knit Fabric Stretch Test

knit fabric stretch test

This simple but important knit fabric stretch test will help you decide what size to choose for a pattern and what to do with the fabric you already have on hand.

Why should you know this?  The best reason I can give you is that it will really let you leverage your stash of fabric at home to create a wardrobe that will make you look and feel great.

As I have mentioned before, there are several knit types; Two-Way Stretch knits, Four-Way Stretch knits, as well as, single and double knits (in both single and double knits the fabric will stretch to a certain percentage).  This article will explain these fabric types in more detail:

The stretchability of the fabric will determine the fit, comfort-ability, and ease of a garment. These are some general guidelines for using stretchy fabric for different types of cloths:

  • 25% stretch or less is considered a minimal stretch knit:   Such as Sweaters Knits, Double knits, Interlock, Tricot, and Fleece.  Normally these fabrics are not meant to stretch lengthwise.  Perfect for sweatshirts, hoodies, sweatpants, t-shirts, dresses, skirts.
  • 50% stretch is a moderate amount of stretch in a knit:  Used for fitted outfits such as t-shirts, dresses, pants without zippers, tops, and flared outfits because of the great drape ability in tops, skirts, and dresses.  Many jersey knits have a 50% jersey.
  • 75% stretch is considered very stretchy fabric and will be best used in active-wear.  Sports Bras, Fitted T-shirts, fitted yoga wear, cycling. Four-way stretch knits are mostly found with this percentage of stretch.
  • 100% stretch in a fabric is normally known as a high-performance fabric.  This type of fabric has a percentage of spandex (15 to 50%)  Best use as swimwear.

How to Perform the Knit Fabric Stretch Test?

You will need to draw a chart to perform this simple test.

Use a piece of paper in a landscape mode and draw a square 4″ (10cm) X 4″ (10cm).

 knit fabric stretch test

Add the rest of the squares.

 knit fabric stretch test

 knit fabric stretch test

 knit fabric stretch test

Now cut a square of the fabric lengthwise 4″ (10cm) X 4″ (10cm) that you want to test.Place the swatch on the square 4″(10cm) X 4″ (10cm).Using your fingers, stretch the fabric until you feel some resistance in the fabric weave, but the pattern does not distort.

The fabric on top is a Jacquard Knit and it stretches comfortably to 25%.  I have used this fabric to make the culottes pants without a zipper.

Using the Results of Your Knit Fabric Stretch Test

I will be using the culottes pants pattern for an example. These culottes are fitted at the lower hips. It has a flare at the hips to accommodate a large bottom.  There is no zipper on these pants. The stretch of the fabric allows me to design them like that.  I am counting on the 25% stretch on each side to be able to hold the pants up.

  • Stretch of fabric:  The fabric I used has a 25% stretchability.
  • The fit of the design:  The culottes pattern pants are fitted on the waist and hips but flare slightly from the thighs.
  • The finished measurements:  The finished measurements on a pattern will let you know more accurately whether a size will fit on your body the way the picture of a garment describes it.  It also determines how much ease is on a garment.  The ease of the garment is determined by the minimum amount a pattern need to fit on the body plus the design of a garment.
  • Your body measurements: Knowing your body measurements to compare with the pattern sizing and finished measurements.

How much fabric stretches will help you decided whether a fabric will be suitable for a particular pattern.

I am well aware that this tutorial is not for the beginner sewist, but for those of you who are a little more experienced would like to explore fabrics and create a wardrobe that is well fitted and more importantly uses the fabrics that are already in your stash.

Join me next time where I will be explaining in detail, sizing, and why it changes from label to label and country to country.

Until Next Time!

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Catherine Huber
Catherine Huber

If I am in doubt about how a knit garment will fit, I cut the pieces out with 1″ seams. This gives me some room to let the seams out if the garment is just a bit too snug.

Sara L M
Sara L M

what about stretch test for headbands wht stretch number is acceptable


This is important stuff. Thank you for sharing. Everyone should be paying attention.