The main concern of the passage is to ---____ .

Paper has been known in one form or another from very
early times. The papyrus reeds of the Nile swamps served
the ancient Egyptians for sheets upon which to inscribe
their records. The Chinese and Japanese, centuries later,
were using something more akin to modern paper in
substance, an Asiatic paper-mulberry, yielding a smooth
fibrous material, being utilised. With the spread of
learning in Western Europe the necessity of a readier
medium made itself felt, and paper began to be
manufactured from pulped rags and other substances.
Other papermaking staples were later introduced, such as
linen cotton and wood-pulp. The chief raw material in the
world paper industry now is wood-pulp, the main
exporters being the timber-growing countries of Canada,
Sweden and Finland.