As you know, there’s a lot to sewing.
You don’t need to know everything all at once, but instead, gather the information over time.
If you’ve been sewing for a bit, you may already know some of this. Bear with me.
The Wonderful World of Fabric Terms
You’re probably already marginally familiar with the difference between knit and woven fabrics. You also probably understand that there are different fibers that fabric is made out of (both natural and synthetic). You don’t need a super deep understanding of these things to move forward, just the basics.
Every fabric that is produced, has something called the “Grain”.
When a fabric is made, regardless if it is knit or woven, there is a direction it is “built” if you will.
In a woven fabric, the cross yarns are woven into the lengthwise yarns, the lengthwise yarns are in the direction that the fabric is “built”. This is also the grain of the fabric.
Knit fabrics don’t already have a foundation of yarns to weave other yarns into, instead, each row of yarns is added to the previous row of yarn loops. The direction these rows are added is the grain.
Incidentally, the grain is parallel to the selvage edge. The selvage being the edge of the fabric where the cross yarns are looped back or tied off.
So, if you have a grain, parallel to the selvage, you also have a cross-grain. That runs perpendicular (right angles or square) to the grain and selvage. This is also runs the width of the fabric.
And, you have a bias … direction… grain. something. Anyway, the Bias, runs 45 degrees to the grain and cross grain.
Regardless if the fabric is knit or woven, the bias direction will always be less stable and appear to be stretchy.
There are other fabrics that have slightly different characteristics and we’ll touch on one of them, in a moment.
It’s a Stretch
By now you might assume that woven fabrics don’t stretch. And knit fabrics always stretch.
But that’s not entirely true.
While a standard woven fabric usually doesn’t stretch, it might have some “give” to it.
But also, many woven fabrics these days have blended fibers like spandex to give the fabric some stretch.
Likewise, there are knits that are constructed in such a way that they barely stretch. They are considered “stable knits”.
How Much Stretch?
The amount of stretch a fabric has is generally measured in percent (%).
A woven might have 0% Stretch. But a woven with spandex might have a 10% stretch.
Nylon spandex swimsuit fabric might have 50% or even 75% stretch.
Percent stretch is measured by taking a known length of fabric then stretching it and measure the new length. The difference between the stretched length and the original length divided by the original length (times 100) is the percent.
So, if you have a fabric and take a 4″ Section and stretch it, and it stretches to 5″. That’s only 1″ more. So, that’s a 25% stretch.
If it stretches to 6″, that would be 2″ difference and a 50% stretch.
Ok, enough maths.
Direction of Stretch
Some fabrics only stretch in the length (on grain), and some only in the width (cross grain). Some stretch in both.
When you’re buying fabric in person, you can feel this and sometimes even tell which one stretches more (length or width).
If you’re shopping online, the seller should indicate the percent stretch. And if it stretches in both directions it will indicate both direction stretch.
You can generally assume that if one of the two directions is not listed as having stretch, it doesn’t.
Fabrics that only stretch in one direction are usually called 2-way stretch fabrics. And fabrics that stretch in both directions are called 4-way stretch fabrics.
You can read this article for a slightly deeper dive into fabrics.