Ancient Egyptian Papyrus
Plant fiber-based paper from ancient Egypt
Wikipedia says: Papyrus was first manufactured in Egypt as far back as the fourth millennium BCE (Before Current Epoch). It is a material similar to thick paper, and was used in ancient times as writing surface. It was made from the pith of the papyrus plant, Cyperus papyrus, a wetland sedge plant.
If you look closely at the photo, you can see the long plant fibers in the Papyrus.
This slide is an antique and dates from the 1880s. This papyrus specimen really is from ancient Egypt.
From Britannica: Papyrus, writing material of ancient times and also the plant from which it was derived, Cyperus papyrus (family Cyperaceae), also called paper plant. The papyrus plant was long cultivated in the Nile delta region in Egypt and was collected for its stalk or stem, whose central pith was cut into thin strips, pressed together, and dried to form a smooth thin writing surface.
Papyrus is a grasslike aquatic plant that has woody, bluntly triangular stems and grows up to 4.6 m (about 15 feet) high in quietly flowing water up to 90 cm (3 feet) deep. The triangular stem can grow to a width of as much as 6 cm. The papyrus plant is now often used as a pool ornamental in warm areas or in conservatories. The dwarf papyrus (C. isocladus, also given as C. papyrus ‘Nanus’), up to 60 cm tall, is sometimes potted and grown indoors.