Both methods are based on the same principle: HEAT MELTS SYNTHETIC THREAD.
In order to illustrate this post I have prepared a band of white waxed thread.
I work with the flame of a lighter. (In this picture I have used the flame of my stove since I had no one to help me with the photography) (I used a flash to let you see the burning thread)
I heat a piece of metal ( in this case it is an old pair of scissors but it could be an old iron).