Patent ID: 8430994
Filing Date: 2013-04-30
Classification: B42D,D21F,D21H,Y10T

Abstract:
1. A method of making a sheet from a fibrous substrate, said sheet having corners and edges joined at said corners; said method comprising the steps of: forming the substrate by depositing fibers on a support surface; forming at least one reinforcing watermark at a predetermined position in the substrate, which at least one reinforcing watermark increases the stiffness of the sheet in the watermarked region, said reinforcing watermark being a positive watermark formed by varying grammage of fibers of the substrate to form at least two adjacent bars of increased grammage relative to the mean grammage of fibers in adjacent areas of the substrate; and further forming at least one raised region within a localized area of the at least one reinforcing watermark, formed by increasing the grammage of fibers, which at least one raised region joins the adjacent bars within the at least one reinforcing watermark to form a localized smooth planar surface, whereas other areas of the at least one reinforcing watermark have a variable profile.