Abstract: A security document or token such as a banknote is provided which has a transparent portion of plastics material which includes a security device. The region surrounding the transparent portion and preferably all the remaining part of the banknote is printed with indicia. The security device includes regions of embossed lines extending at different angles to each other defining different shapes that are visible to a greater or lesser extent upon transmission and reflection of light as the note is tilted, rotated or viewed from different angles relative to the light source. The embossed lines in some of the regions are finer than coarser and deeper and more widely spaced lines in the other regions. The coarser, deeper lines are of such a thickness and width as to be detectable by touch in addition to being visible by the naked eye.

Abstract: A self-verifying security document, such as a banknote (1) comprises a flexible sheet formed from a plastics substrate (2) bearing indicia (3). The sheet has a window (5) of transparent plastics material which includes self-verification means (11) for verifying a security device (4) provided at a laterally spaced second portion of the sheet when the sheet is bent or folded to bring the window (5) into register with the security device (4). The self-verification means may be an optical lens (11) for reading an area of microprinting (10). In another embodiment, the self-verification means may be an optical filter (21) for viewing an area (22) printed with metameric inks. In other embodiments, the self-verification means and the security device (4) may be polarising windows (31, 32) or Moire inducing patterns (41, 42).