wax tablet

A wax tablet is a tablet made of wood and covered with a layer of wax, often linked loosely to a cover tablet, as a "double-leaved"  diptych. It was used as a reusable and portable  writing surface in Antiquity and throughout the Middle Ages. Cicero's letters make passing reference to the use of cerae, and some examples of wax-tablets have been preserved in waterlogged deposits in the Roman fort at Vindolanda on Hadrian's Wall. Medieval wax tablet books are on display in several European museums.