String.

The uniqueness of a piece of string.

It combines philosophical properties such as; How long is a piece of string?
An end is both a beginning and an end.
Each individual strand is weak but combined it greatly increases its total strength.

In Cosmology there is the string theory.

You can wear a string vest and enjoy the property of its retaining body heat.

String could be made of cotton or a host of other materials.
It is interesting that the second wedding anniversary is represent by cotton which can be both weak and turned into strong string.

In my own life I am happy that my marriage has long past the test of cotton and become string.