Abstract: A security device includes an array of microimages which, when viewed through a corresponding array of substantially spherical microlenses, generates a magnified image. In some cases, the array of microlenses is bonded to the array of microimages.

Abstract: Apparatus for handling digital representations of documents which are to be provided with a number of images. The apparatus comprises a first store for storing digital data defining the image content of each pixel of each image and a color generator for generating data defining, independently of the image contact data, the color of each pixel of each image or combinations of images as defined by a user. A processor selectively combines the image content data and the color data to enable selected images to be viewed separately or in combination as allowed by the layering structure provided.

Abstract: A copy indicating security device includes at least one symbol defined by a first arrangement of print elements, the or each symbol being provided in a background defined by a second arrangement of print elements. Under normal viewing conditions the security device presents a substantially flat tint to the eye. The first and second arrangements of print elements differ from one another so that on copying the device at least one of the symbols is revealed. The perimeter of the or each symbol is generally irregular.

Abstract: An authenticatable item and security device carry a number of symbols (4A, 4B, 4C, 6A, 6B, 6C) identifiable to the naked eye, there being at least two sets of at least three symbols. All the symbols within a set are substantially identical, are positioned in a non-overlapping, regular geometric arrangement, and at least one common viewing angle of inclination, exhibit substantially the same optical performance, the optical performance varying with inclination viewing angle.