IMPROVEMENTS IN MAKING SHEETS

摘要

The invention relates to improvements in methods of making sheets for security documents having edge or corner reinforcing watermarks (13, 18) and a surface applied feature (15) and a method of making a sheet from a fibrous substrate, said sheet has corners and edges joined at said corners. The method comprises the step of forming the substrate by depositing fibres on a support surface and forming at least one reinforcing watermark (13, 18) at a predetermined position in the substrate. The reinforcing watermark (13, 18) increases the stiffness of the sheet in the watermarked region and is a positive watermark formed by varying the grammage of fibres of the substrate to form at least two adjacent bars (13a, 18a) of increased grammage relative to the mean grammage of fibres in adjacent areas of the substrate. At least one raised region (17) is formed by increasing the grammage of fibres, which joins the adjacent bars within the at least one reinforcing watermark to form a smooth planar surface. This surface is suitable for a subsequent application of a substantially planar security feature (15) to a portion of at least one surface of the substrate across the smooth planar surface.