X-Rays and paper
Dard Hunter, the paper historian, defines paper as a thin sheet ‘which must be made from a fibre that has been macerated until each individual filament is a separate unit: the fibres intermixed with water, and by the use of a sieve-like screen, the fibres lifted from the water in the form of a thin stratum, the water draining through the small openings in the screen, leaving a sheet of matted fibre upon the screen’s surface’ (Hunter 1978). This definition excludes other chemically similar products such as barkcloth, woven textiles and papyrus, as they are made by different methods to produce structurally distinct materials. It is thought that paper first appeared in China in AD 105, but it was not until 500 years later that it began to be made in Europe. Before paper became common, the principal surfaces used to write on were wood, wax, leaves, bark, stone, metal, clay tablets and parchment.