Today when I was visiting the marketplace for some new pots, I came across a merchant selling these odd, a bit fabric-like white sheets. He told me that the Egyptians make these from reeds to write on them.
Personally, I don’t see a need for such a material. Just use a clay tablet like a normal person!
I can carry a whole stack of papyrus with the same weight as one slab of clay. Also if the clay falls down, it breaks. Papyrus survives falls easily. It’s so light, it floats on the air.