You will need:

1. A polyester thread about 50cm (to readjust according to the size of your wrist)

2. An interlayer

3. Scissors

4. A lighter

Step 1 :

Take one end of your thread and pass it through the hole in the interlayer, then iron the thread inside the hole, so you make a small loop. Always the same end of thread, pass it in the loop and push the interlayer to hide the knot.

2nd step :

Set the bracelet to the size of your wrist
Place the thread over the bracelet and catch the thread with your left hand, passing it behind.
Roll again 3 times to form 4 loops, and pass the thread through the 4 loops.
Pull to tighten the knot.
Make sure that the knots are as close as possible to the interlayer. So you can put on and tighten to fit your size.
Repeat this step to tie a knot on the other side.

Step 3:

Cut the excess thread, leaving a small end.
With a lighter, burn the end of the wire to complete the knot. This allows the knot to not undo, and makes the bracelet stronger.
The bracelet grows as the knots move closer to the interlayer.