Paper including watermarks and/or embossings
The invention relates to improvements in paper, and in particular to the use of watermarks and/or embossings for strengthening paper sheets and documents made therefrom. The invention therefore provides a sheet of paper having at least three corners and three sides joined at said corners, wherein corner reinforcing watermarks are provided at each of said corners. Alternatively, or in addition, corner reinforcing embossings are provided at each of said corners.
1. A sheet of security paper having at least three edges and at least three corners, said corners being formed where a pair of adjacent edges adjoin each other, said sheet having a mean paper grammage and a mean stiffness, and said sheet including reinforcing watermarks at or covering a middle of at least two edges, wherein said reinforcing watermarks comprise one or more stripes, each of which stripes is substantially parallel to an edge of the sheet, said stripes having a paper grammage greater than said mean paper grammage and providing a stiffness along said edges greater than said mean paper stiffness to thereby increase the paper stiffness in a direction parallel to edges of the sheet.
2. A sheet of paper as claimed in claim 1 , wherein the reinforcing watermarks comprise a plurality of substantially parallel stripes.
3. A sheet of paper as claimed in claim 1 , wherein the reinforcing watermarks are positive watermarks.
4. A sheet of paper as claimed in claim 1 , wherein the stripes are straight.
5. A sheet of paper as claimed in claim 1 , wherein the stripes are undulating.
6. A sheet of paper as claimed in claim 1 , wherein the stripes have a width in a range of 1 to 2.5 mm.
7. A sheet of paper as claimed in claim 6 , wherein the width of the stripes lies in a range of 1.5 mm to 2 mm.
8. A sheet of paper as claimed in claim 1 , wherein the reinforcing watermarks are joined by watermark patterns.
9. A sheet of paper as claimed in claim 1 , wherein the reinforcing watermarks are provided at or covering the middle of each edge of the sheet.