I start by giving credit to DRUMBUM11 for his meathod used in his instructible https://www.instructables.com/id/Stretchable-Paracord-Bracelet/ . His project does not include the elastic band that I use in this project. I am simply expanding on his project.
I have made a lot of paracord bracelets in the past few months and I have found connecting the buckle to be troublesome and in the end I have burns and, because of the curved buckles I was using, you could never wear both sides of the bracelet (I always use two colors). Using this technique there is no buckle or knots, you can use both sides of the bracelet and its as easy to put on as slipping it over your hand!
Step 1: Materials
The materials used in the project are pretty much the same as every paracord instructible on the site!
2 three foot lengths of paracord in the colors of your choice
Elastic Hair Ties (preferably a color that will blend in)
Step 2: Tie the First Knots
It helps to melt both ends of the cord before you get started. Once you have that done, tie the first knot. I like to describe this knot as the first knot you would tie when you go to tie your shoes. Then you need to take your hair tie and thread the right side of the knot through it. Now take the two short ends of your cord and finish the knot.
Now because the hair tie is already a complete circle a really small portion of it with show on one side of your bracelet. However, it will be right next to the melted section at the end so when you turn the bracelet so that that section is on the palm side of your wrist it will also hide this. If you used a similar color to your bracelet you shouldn't be able to tell anyway.
Step 3: The Cobra Weave
Now your free to do as you have for every cobra weave paracord bracelet. If you don't know how to do it there are many instructibles on the site that are much better at explaining it than I am. Start weaving along the hair tie until you reach the other side. You should not tie the knots very tight. This will cause the bracelet to not stretch nearly as much and you might not be able to put it on. If you feel like the contracted form of the bracelet is too small just give the hair tie a tug and you should have a little more room for more knots. Repeat this till you feel like the contracted form is just a little small for your wrist. You want to give the elastic some room just in case it loosens up a little bit over time.
Step 4: Finishing the Bracelet
When you get the bracelet to the length you want cut the ends to about a half inch. Melt both ends then quickly stick them together. Allow them to cool for about 30 seconds. I have found that cutting one side and doing it first works better. If you cut all four ends first one side might slip out while you melt the other.
Step 5: Put It On!!!
After you let the ends cool you have a completed bracelet! No excessive knots or annoying plastic buckles!