Imagine a fabric that stretches so well that it can hold at least 5 of you if the clothing is your normal size and then return to the original size when you are done stretching, without a single fiber getting damaged – no bagging, no sagging!
Yes, spandex or elastane fabrics, made from polyurethane do stretch that way.
Spandex was first introduced in the 1959, by the DuPont Company. According to the code of federal regulations, spandex is a “manufactured fiber in which the fiber-forming substance is a long chain synthetic polymer comprised of at least 85 percent of a segmented polyurethane”. And today, it is rare to see fitting clothing without some amount of spandex in them.
This stretch & recovery quality is just the reason why it is the favorite for making all kinds of body-fitting clothes- swimsuits, dancewear, gym wear, innerwear, and even your everyday tops, pants, and pencil skirts.
As a stretchy fabric, there is no parallel to spandex – even the rubber, which we all thought was the most stretchy, fails in front of this stronger, more durable and prettier material.
It is smooth, supple and soft, and therein lies all its trouble. Slipperiness and uneven feeding of layers are the results of these positive qualities.
There are three types of spandex fabrics. One is a pure spandex fabric, and the other is a blend. The Blended spandex includes cotton spandex, linen spandex, and rayon spandex blends. These are woven fabrics. Then there are knits containing spandex. 2-way-stretch knits contain spandex are very popular for dressmaking. Four-way stretch jersey with elastane is a good choice for making active wear. All of them have that desirable quality – stretch in different levels.
And all these fabrics are to be treated slightly differently when sewing though the basic principles are the same.
In this article I will cover:
1. CUTTING DIRECTION
Check out the stretch direction of the fabric. Determine the way the stretch runs (lengthwise, crosswise or both) and adjust your pattern accordingly.
Ensure that the main seams are along the stretch. When you sew across the stretch there might be puckering. A puckered seam is not a nice sight on a beloved garment
Aside from minding the cutting direction, another important thing is to cut spandex in single layers – this is to account for its splippery nature. You can use a rotary cutter on a self healing mat to cut spandex easily.
2. SEWING NEEDLES
The problems when sewing with spandex are minimal – but they can be annoying – like skipped stitches. These are mostly because the wrong needles are used.
Looking at the structure of spandex you may think that it will be troublesome like sewing vinyl, leather etc. You may wonder whether your needle will leave holes. But no. Sewing spandex is no trouble that way. It is just like any other fabric. You just have to be a little more careful.
For sewing woven spandex blends and spandex woven fabrics, use a sharp needle of size 70/10 or 80/12. If not, use a universal needle with the numbers 70/10 or 80/12 or 90/14, depending on the weight of the fabric. For the thinner variety the 70/10 needle is preferred.
For knit spandex fabric use stretch needle – a ballpoint/jersey needle of size 75/11 can be used for sewing most knit spandex fabrics. For sewing hems, you can also use a twin needle.
If you have a cover stitch machine, use that.
3. SEWING THREAD
You need a stretchy thread to accommodate the stretch of the material, so do not use pure cotton thread. A cotton-poly mix thread or a 100% Polyester thread can be used.
4. PRESSER FOOT
Use a walking foot for smooth even feeding of the fabric. Another useful presser foot is a roller foot. But yet another rare but good presser foot for maintaining the stretch of the stitch is a knit foot.
You have to attach the knit foot on your sewing machine so that the tall lever you have on the foot is placed on the back of the needle bar screw on your sewing machine.
5. SEWING TENSION
Decrease the tension when you sew spandex fabric. A 3 would be prefered. If you can reduce the pressure on the presser foot, do that.
6. STITCH SELECTION -TYPES
The problem with using normal straight stitching with elastane fibers is that the seam can break off when your fabric stretches beyond normal. So your stitch has to accommodate the stretch of your fabric.
For full Spandex fabric – If you have a serger, use a 3 or 4-thread overlock stitch.
If not, use a stretch stitch or narrow zig-zag stitch. (Stitch length 2, stitch width -1.5 or 1)
Blends of spandex – You can use a straight stitch depending on the percentage of spandex/elastane fibers. If the spandex is more, you will have to use a tight zig-zag stitch
On some seams you may find an uneveness, after stitching. You can try to reduce this with topstitching.
Many prefer to use twin needle stitching on hems. Blind hem is a good hem treatment for spandex.
7. STITCH WIDTH AND LENGTH
For straight stitching for wovens, use a stitch length of 2.5. For knit spandex, use a stitch length of 2.0 and a stitch width of 1.5
8. PREWASH OR NOT
Fabric with full spandex fibers is not going to shrink in the wash now or later. But if you have blended fabrics with cotton and linen fibers, the fabric is bound to shrink if you sew first and then wash. So they should be prewashed.
Prewash in cold water. Ensure that you are not using any detergent with bleach. Bleach is damaging to spandex fibers.
9. NO PRESSING?
Spandex fibers and high heat are a strict no no. Do not think about pressing the seams open with your high heat iron. But if you want to alter the look of the fabric, do use heat. The fabric is heat settable.
If you really want to press, do that fast or steampress and then finger press. Do not leave the iron too long in one position directly on the fabric – as a synthetic fabric, it will melt in place.
You need interfacing that will also stretch. In fact the interfacing should stretch as much as the fabric. A knit medium-weight fusible interfacing can be an apt choice with spandex /blends
Try not to use pins on outside areas – pins can leave holes on spandex
Do not stretch spandex while cutting or stitching.
Interesting reading on sewing spandex – https://www.instructables.com/How-to-sew-spandex