Notes and Reflections on Books and Media
by Hannah Leitheiser
Pliny the Elder
'M. Varro informs us that paper owes its discovery to the victorious career of Alexander the Great, at the time when Alexandria in Egypt was founded by him; before which period paper had not been used, the leaves of the palm having been employed for writing at an early period, and after that the bark of certain trees. In succeeding ages, public documents were inscribed on sheets of lead, while private memoranda were impressed upon linen cloths, or else engraved on tablets of wax' - The Natural History, Pliny
Of course, that's why pencils are said to contain lead.