Papyrus, a tall, graceful, sedgy plant, supplied the favourite writing material of the ancient world, and many priceless records of antiquity are preserved to us in papyri. The pith of the plant was pressed flat and thin and joined with others to form strips, on which records were written or painted. The above is a photograph of a piece of Egyptian papyrus, showing both hieroglyphics and picture-writing. The oldest piece of papyrus dates back to B.C. 3500.