Reinforcing watermarks used to strengthen sections of a paper sheet, such as the corners or sides of a banknote

摘要

Paper sheets 10 and documents made therefrom, such as banknotes, are strengthened using reinforcing watermarks 11, 12 which are applied to the sheet as a positive pattern. The sheet of paper 10 has at least three corners and has reinforcing watermarks provided at each corner 11 or side 12 which prevent damage due to e.g. folds or dog-ears. The paper may be further strengthened by overlaying the reinforcing watermarks with an embossing or by creating a continuous reinforcing watermark around the whole sheet.