To test the stretch percentage of any fabric, take a fabric square 10 cm x 10 cm or grab a section of the fabric you want to test that is 10 cm wide, use my free PDF stretch gauge to help you calculate.
Click the link at the top of below to get your free PDF copy.
Do not include the selvage in your test piece.Mark or make a note of which grain you are stretching first –
It is important to note which grain you are stretching first, so mark the weft, this goes from left to right and the warp, this runs parallel to the selvedge.
Take the fabric and fold in half if you are working with a cut piece, do not stretch on the cut edge.
Now stretch the fabric until you feel it wants to spring back, don’t over stretch. Make a note of the stretch percentage of the weft first and then the warp. Also it is important to note if the fabric returns to its original length. Fabric that does not have good recovery is not suitable for lingerie or tight fitting garments as it will become baggy and ill fitting very quickly!
Stretch the warp – folded fabric
Stretch the weft – folded section.
For example – The weft of my sample piece stretched from a cut square of 10 cm to 14 cm and the warp to 12 cm. weft grain travels around the body so this perfect that it has more stretch. Therefore the stretch percentage of the fabric is 40% in the warp and 20% in the weft. Now I also know my Direction Of Greatest Stretch (DOGS) and my Direction Of Least Stretch (DOLS), important information in lingerie making!
Knitted fabric is constructed with loops, as opposed to woven fabric, which has a woven structure! Sometimes it’s something that sewers don’t realize. Sewing patterns for knitted fabrics such as Jersey are different to those for regular woven fabrics such as cotton.
The loops of a knitted fabric allow it to cling and stretch to the body much better than a woven fabric, as the loop structure can move around and expand. Some knitted fabrics rely on the structure of the fabric alone to help them stretch. There are also knitted fabrics that are a little more technical and they have an extra element called spandex, or Lycra (trade name) and this super stretchy filament allows the fabric to stretch and more importantly recover even more!
I can’t lie, an overlocker (serger) is the best thing for stretch and knit fabrics, the stitch is designed to allow it to stretch with the fabric. So when we are using a normal sewing machine, we are doing our best to avoid the problems we encounter when sewing a stretch fabric. So if you are a keen sewer and want to produce lots of stretch garments, then the best investment you can make is an overlocker (serger)!
If you have a regular sewing machine you can make a pretty good job too, by working in a particular way and using a particular set of stitches. You may well have a stretch stitch on your machine, they are normally not so good, but don’t let me put you off, give it a try, sew a sample and give it a good stretch and see how it reacts.
Firstly though, lets take a look at the needle you are using. Ball point and stretch needles are now both widely available. They both have a rounded tip, as opposed to a regular ‘sharp point’ needle. The rounded tip helps the needle enter the structure of the fabric without damaging the fibers. The stretch needle is slightly less rounded than the ball point needle. Ball point needles were designed for heavier looser knitted fabrics and more modern stretch needles are designed specifically for the more technical knits I mentioned such as spandex and stretch lace. Again, practice on a swatch of fabric and see how they perform. In the past I have found that certain knit fabrics much prefer a regular sharp point needle and the special needles for knits didn’t perform as well and skipped stitches, so you never know until you try to sew!
The best stitch for knits, on a regular sewing machine, is a zig zag stitch. You can adjust the length and width to suit and the structure helps it stretch. The only downside is that your seam can look a little bumpy from the right side, so make a few samples and see how they look.
There is also a three step zig zag stitch, this looks great, but it is forcing a great many stitches into your fabric and this can cause waving and stretching that you don’t want, so again, a sample is the best test. Three step zig zag in my experience is less effective in most cases than the zig sag stitch.
In a previous post I covered stitch width and length so that may be worth a look for you.
Stitch width and length reference – a visual guide
Some tips I can give you if you are having problems are –
Try not to stretch out the fabric as you are sewing.
If your machine has the ability, take some pressure off the feed dogs, usually you can do this, but you may have to google that for your particular machine.
A good quality nylon or polyester stewing thread can make all the difference, if you are having problems and are using a cheap thread, then this is most likely the problem.
A twin needle can also be used on most machines, again you can take a look at this for your particular machine and give it a try! This is certainly an idea for another post!
A hope this very quick discussion has helped a little, practice samples and experimentation are the key and if you have any questions or comments then please ask!
