The study of watermarks is complex and difficult.

They first attracted the attention of scholars in the

early eighteenth century, and during the nineteenth

and twentieth centuries a number of studies in many

languages appeared, dealing with the historical impor-

tance of watermarks. Almost every scholar who has

written on the subject has advanced a different theory

of their origin, utility, and meaning. Thousands of

watermarks have been reproduced and recorded from

the thirteenth century onwards but no definite theory

of their purpose or study of their development has

been accepted?