What is the difference and why does it matter?
It helps to know the difference between knit and woven fabrics because they each have their own ‘world’ when it comes to making the fabric and then making garments with them. Many fabric suppliers often specialize in one category or the other. If your fabric is a knit, you can’t source it from a wovens only supplier, and vice versa. When it comes to manufacturing clothes, factories often also specialize in handling either knits or wovens, though some places do handle both. The needles, threads, and handling in sewing are different from one category to the other. For example, if you are making a legging, you are going to want knit fabrics and a sewing plant that can handle that stretchy material well.
Take a close look at your fabric. Can you see if the yarns (the threads that make up the fabric) are crossed or looped? Looped fabric is knit like the image shown here in blue, and crossed fabric is woven like the image shown in green. The knit loops often look like tiny rows of braids while the woven looks more like a basket. The knit is also made from one continuous yarn while a woven is made from lots of separate yarns.
If it’s too small to see the construction of the fabric, try the stretch test. Does the fabric stretch easily width-wise? If it it does, that’s called 2-way stretch because it stretches left to right and back. If the fabric is a 4-way stretch, it will have stretch lengthwise as well. If the fabric feels rigid when you pull on the length or width, then there’s a good chance it is woven. Make sure you are not pulling on a diagonal because a woven will have some give that way. It’s called the bias; it’s a 45-degree angle to the main warp (vertical) and weft (left-right) lines. The bias is great for making fabrics looks drapey and flowy on body, but also uses up more fabric on the cutting table and therefore costs more.
You can also try the wrinkle test and the fray test. Wad your fabric into a tight ball and release it. Does it relax back to its original smooth state? Or does it hold some of the wrinkles? Knits will relax back and wovens often stay a bit wrinkled. It’s just the nature of the materials. For the fray test, you’ll need to cut your fabric and find a single yarn or yarns and pull on them. If they come off in tiny loops or one continuous strand that unravels like a sweater, you’ve got a knit. If the yarns pull out in a straight line, it’s likely a woven.
Still not sure? You can email a garment pic & a close up pic and I may be able to tell from the photos. Just reach out on our short consulting form here to start a conversation - https://www.developapparel.com/consulting