The main function of the flag is to fly in the wind.
The flag must be lighted, because it need to fly in the light breeze, but also solid, in order not to tear in the strong wind. The flag must be durable with long life time and still colourful during different weather changing. The best material for the flags is polyester. The fibre of the synthetic polyester was invented in England in the year 1941. Industrially it started to be produced in the year 1947. Today it is the mostly used textile fibre. By knitting or weaving is produced the polyester material for the flags. After it is bleached and the basic material is obtained, then it is used for printing of the designs for the flag.