Some of you might think that you just make a fabric tube and thread the elastic through with a safety pin or a bodkin. While that is a great method for inserting elastic in some instances, it is not the best one for bikini straps. Why? The free-floating elastic inside the strap likes to twist, and is nearly impossible to flatten out. Also, it never seems to lie flat once it has been stretched a bit.
The method I show here keeps the elastic straight and flat. Ready to try this different method which I call "Elasticated Straps"?
First, a bit of math. Cut a strip of your swimsuit fabric 4 times the width of the elastic you are planning to use. I am using Filpar siliconized rubber for the strap and it is 3/8" (9 mm) wide, so I will cut my strips 1.5" wide (36 mm). I figure I need 36" (91 cm) per strap, so I cut 2 strips. It would be nice to do the strap as one long piece but that would be difficult to turn, so I will do it as two.
Now position the edge of the elastic against the edge of the fabric. I show it pinned here but in reality, the strip has been glued as in the photo above. The distance from the fold of the fabric to the edge of the elastic should equal the width of the elastic.
Zig-zag the elastic to the folded strip. You can see here how I have cut 4 or 5 layers of 1/4" masking tape and stuck them to the machine bed. They act as guides for the strip so I won't weave all over the place. You could also serge the elastic to the strip.
This is what it looks like when it is done.
Now to turn it! You could use a pin or a bodkin, but I use the Turn-it-all, which I call "the Stick and the Straw". The Straw is a hollow tube.
Make sure one end of the tube is sewn across the end.
The Straw part of the Turn-it-all needs to be able to fit into the tube. Push it in the open end until the closed end touches the end of the Straw.
Use the Stick (a wooden dowel sized to fit inside the Straw) and push the closed end of the tube into the Straw. At the same time, push the fabric on the Straw toward the Stick.
Keep pushing the Stick and the fabric. It will slide quite easily once you get going.
Once the fabric tube has all been turned, take the Stick out of the tube. I usually just cut off the closed end of the tube so I can get the Stick out easily. Here is the fabric tube with the elastic stitched inside it.
I am going to use these straps on the bikini, attached to the triangle cups I covered, by some small rings. But that's a job for tomorrow. Stay tuned!