Fibers or
fibres (see spelling differences) are a class of hair-like materials that are continuous "'filaments"' or are in discrete elongated pieces, similar to pieces of
thread. They can be used as a component of
composite materials. They can also be
matted into sheets to make products such as
paper or
felt. Fibers are of two types: natural fiber, which consists of animal and plant fibers, and man-made fiber, which consists of synthetic fibers and regenerated fibers. The earliest evidence for humans using fibers is the discovery of
wool and dyed
flax fibers found in a prehistoric cave in the
Republic of Georgia that date back to 36,000
BP.