Using elastic thread in the bobbin doesn't make the material gather, you have to do it yourself. This is called shirring. You'll need to use a zigzag stich, make several rows of stitching, secure the top thread and the elastic thread on one edge of the fabric and then pull the elastic threads on the other edge to produce the gathering or shirring.
Haberdashery.
start with a single but keep one very long end . take your next bead and thread it on the elastic then thread the elastic two beads over and repeat
There are all kinds of threads used to sew elastic bands into pants. One can use many different threads to sew elastic into pants like wool, cotton, or simple fabric.
To use a needle and thread could be called sewing.To use a needle and thread could be called quilting. To use a needle and thread could be called embroidery. To use a needle and thread could be called suturing.
Hand wind the shirring elastic onto your bobbin. Use same color standard thread for the top. If you are going to need a hem, hem it first because it's harder after shirring. Simply sew the lines from one end of the line to the other, about 1/2 inch apart. The shirring elastic will automatically gather the fabric for you. Be sure to tie the ends to keep them from pulling out, or anchor them with extra stitching.
He lost the thread of his argument.
Golf balls about 7-10 years ago used to wrap the core in a thin elastic band. This was because it is a very energy responsive material and allowed good distance from the ball. This concept is not used anymore as the cores are so good now, there is no need for the elastic bands.
Hand wind the shirring elastic onto your bobbin. Use same color standard thread for the top. If you are going to need a hem, hem it first because it's harder after shirring. Simply sew the lines from one end of the line to the other, about 1/2 inch apart. The shirring elastic will automatically gather the fabric for you. Be sure to tie the ends to keep them from pulling out, or anchor them with extra stitching.
normal thread is used, the thread used in Tailor work. It is just the way they use it, it seems magic.
elastic potential energy is stored by the forces within a disorted elastic object
Bungee cord would not be of any use as a bow string, strings are not elastic! Traditionally longbow strings were made of linen thread, several strands heavily waxed, there really are no other suitable "Household" materials, that I know of. Bowstring material must be immensely strong, and it is really necessary to use commercially available thread to make a string. Dental floss is a good analog readily available. Typically you would use a pegged board and take 10 or 12 strands of thread or floss and then wrap that with more thread or floss.