Sew, What's New?

Curating sewing and quilting talent, techniques, and tutorials, since 1997.

Elastic Thread Techniques: Bobbin and Chain Looper

Preparing for both my new DVD set on sewing knits, ‘STRETCHING YOUR KNIT SEWING KNOW-HOW‘ AND a new episode for It’s Sew Easy Series 900 on Elastic Thread, I’ve learned even MORE since my last post!  Below is a chambray (woven) peasant-type top I designed.  It features cover hems at the sleeves and lower hemline, a bias edge/casing at the neckline, and Elastic Thread in the Chain Looper to shirr the sleeves and waistline.  Thanks to BROTHER for the PaceSetter Compact Cover Hem Machine… 2340CV .  
chambraygarment

 

To review some, and ADD even more discoveries….

Fatter threads will shirr more than thinner threads.

Fatter threads will shirr more than thinner threads.

Thin isn’t bad, it will just shirr less-so.  Dritz is a commonly found brand of elastic thread (available black and white) that is thinner and used for those examples in my experimentation.  On the other hand, StretchRite (now, I find being re-packaged as ‘Singer’) is fatter, and will shirr, draw up, more.

Thread in your lap, wind directly to the bobbin with slight tension between fingers only as you guide the thread up and down the bobbin.

Thread in your lap, wind directly to the bobbin with slight tension between fingers only as you guide the thread up and down the bobbin.

My opinion is that winding elastic thread onto a bobbin by hand is inconsistent at the best.  Instead, follow the directions in the caption below the photograph above.

lengthnsteam

Longer Stitch Length will shirr more tightly than shorter stitch lengths.

The longer the stitch length, the tighter shirring you’ll create.  Steaming by hovering a good steam iron over the elastic thread after stitching will shirr the work even MORE.  Note in the right sample above, that steaming shrunk the work 30% more.

Less pressure allows fabric to shirr more.

Less pressure allows fabric to shirr more.

This is a NEW discovery of mine!  In my sewing on knits experimentation, I’ve found that using the decorative stitch foot (that has a groove all through the bottom of the presser foot allowing for the build-up of decorative stitches to feed through below the foot) actually subtly reduces the pressure on the fabric.  It makes sense, in this case then, that less pressure allows the fabric to draw up more.  Compare the 2nd sample in the photograph above done with the Decorative Stitch Foot to the photo at the left done with the flatter bottomed regular stitch foot.

Make SURE that the bobbin thread is CAUGHT n the TENSION.  More about that at my first Blog Post: http://blog.londasfiles.com/?p=2002

AND AND AND, do NOT use an automatic thread cutter!  Doing so will 'lose' the bobbin thread from the tension, so just do it the 'old fashioned way' and cut the threads, pulling plenty of thread out each time you stop.  

Elastic Thread in a chain looper will gather more than on a sewing machine.

Elastic Thread in a chain looper will gather more than on a sewing machine.

See above how to increase the shirring ratio even MORE by using a serger with a chain looper.  Cover Hem Machines have chain loopers, but also 5 thread or more servers, and some 4 thread servers that do cover hems have chain stitch capability.  The elastic thread is put in the chain looper.  I found the following adjustments were needed:

* Set stitch length to the longest stitch.

* Set differential feed to the highest number (mushing in extra fabric with every stitch).

* Be sure to use a thread net on the elastic thread to control it.

* Tension Adjustments:  Needle – loosen by 1 notch.  Looper – loosen by at least 3 notches from regular chain stitch settings.  I actually loosened the Chain Looper tension to ZERO.  I found these changes necessary only when I went to serge 54″ lengths of fabric.  It seemed that the tension on the chain looper just increased more and more and more, then finally broke.  When I was working on 10″ pieces, never had a problem….

Parallel rows shirr a Sleeve.

Parallel rows shirr a Sleeve.

anglestitch

Parallel rows need to be secured at seams with stitching through each row the other direction with small straight stitches…but it is a real ‘pain’ to stop and start when using elastic thread in the chain looper.  INSTEAD, I found it easier to continue, just angling to continue as you see I’e done in the photograph above as the left upper stitching angles down to become the 2nd row at the right, and then the same for the next row.  To secure with this method, leaving  a long length of the elastic thread at the beginning and the end to then securely double square knot is the final step.

To be really scientific about how much fabric you need to start with in order to end up with the shirred area to end up a certain size…..my ‘numbers-smart’ hubby helped me figure out the following proportion formula.

First, you need to determine how much fabric is needed, depending on the settings decided upon for pulling up the fabric as determined in testing:

1.  TEST a 20″ strip to refine technique and to determine the ratio of ‘pull-up’.

2.  Set up a proportion as follows and solve for X

L2S : L2E = X : LD

Length to Start (L2S) is to the Length to End (L2E) as HOW much length do I start with (X) is to what Length is Desired (LD) when gathered (which will still stretch) – for example…circumference of a wrist, or a waist or midriff.

For Example:  

In a test sample, 20″ fabric gathers up to 14″  so that is 20:14  (L2S: L2E)

X is how much length of fabric I then need to start with (this is what you are solving for)

if I want it to end up gathered to 10″

20″: 14″ = X : 10″

14X = 200

X = 14.28

 For even MORE details – be sure to check my original Blog Post on Elastic Thread in the Bobbin - 

http://blog.londasfiles.com/?p=2002

 

 

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