For this purpose accurately take out on one thread up and down fabrics. These threads are accurately fire by a match. 

If the thread burns quickly, in regular intervals, with a bright flame and smells, as if the paper burns, and ashes, which fall from a light touch - it means that a fabric from a vegetative fiber (cotton, flax) or from viscose.

Acetate silk also burns quickly. On the thread end there are ashes in the form of a hard black-brown small knot. At burning exhales a smell of acetic acid.

Kapron and nylon do not burn, and form a soft small knot.

Wool and natural silk burn badly. On the thread end is formed the black small knot ashes, which fall from a light touch. At burning exhale a smell of a burnt bone.