What is Papyrus?
When the Egyptians began to write, about 3000 BC, they wrote from the beginning in ink, on papyrus (pah-PIE-russ). Papyrus is a plant that grows wild all over the Nile river valley, which is to say it is very common in Egypt. You can cut the long stalks and soak them in water until they rot a little, and then you lay a lot of these stalks next to each other, and a lot of other stalks on top, crossways to the first ones, and then you pound them flat, until all the stalks get mashed into all the other ones, and you have something a lot like paper.
At first papyrus was only used in Egypt, but by about 1000 BC people all over West Asia began buying papyrus from Egypt and using it, since it was much more convenient than clay tablets (less breakable, and not as heavy!). People made papyrus in small sheets and then glued the sheets together to make big pieces. (a craft project?)
The Greeks and the Romans also used a lot of papyrus, all bought in Egypt because that is where papyrus grows. But it wasn't cheap! One sheet probably cost about what $20 is worth today. So when the Islamic empire learned how to make paper from rags from the Chinese about 700 AD, people quickly stopped using papyrus, even in Egypt.
Bibliography and further reading about papyrus:
Papyrus: Structure and Usage, by M. L. Bierbrier (British Museum, 1986). (Out of print)
The History of Making Books: From Clay Tablets, Papyrus Rolls, and Illuminated Manuscripts to the Printing Press, from Scholastic Books (1996). For kids, translated from a French original.