Abstract: The invention relates to improvements in security substrates and in particular to fibrous security substrates, such as paper, incorporating a watermark. The security substrate comprises a fibrous base layer, having a normal base fiber density, said base layer incorporating a watermark consisting of a plurality of alphanumeric characters. Each character comprises dark and/or light regions, the dark regions being formed by more densely deposited fibers than the normal base fiber density and the light regions being formed by less densely deposited fibers than the normal base fiber density. The density of the fibers in any region is substantially uniform such that there is no gradual change of tone between the light and dark regions. Each dark and light region adjoins at least one light and dark region respectively and an area of normal fiber density.

Abstract: The invention relates to improvements in security substrates and in particular to fibrous security substrates, such as paper, incorporating a watermark. The security substrate comprises a fibrous base layer, having a normal base fibre density, said base layer incorporating a watermark consisting of a plurality of alphanumeric characters. Each character comprises dark and/or light regions, the dark regions being formed by more densely deposited fibres than the normal base fibre density and the light regions being formed by less densely deposited fibres than the normal base fibre density. The density of the fibres in any region is substantially uniform such that there is no gradual change of tone between the light and dark regions. Each dark and light region adjoins at least one light and dark region respectively and an area of normal fibre density.

Abstract: A security device comprises a holographic or diffractive optically variable effect generating structure which, when viewed normally i.e. perpendicularly to the plane of the device, replays at least one composite image, the composite image being defined by at least a pair of discrete image elements, the structure being such that at least two of the discrete image elements of the composite image have different optimal replay angles.

Abstract: The invention relates to a security element for security paper for banknotes and the like having both aesthetic and anti-counterfeitable qualities. The invention comprises a security element for wholly or partially embedding in security paper comprising an elongate strip of a light transmitting polymeric substrate. The substrate bears a reflective metallic layer on at least one surface thereof in the form of a design. The design comprises at least one repeating geometric pattern of which one of more of the frequency, instantaneous amplitude and/or maximum amplitude of the pattern varies along the length of the element and design having at least one non-linear boundary.