Abstract: The present invention relates in one aspect to a method of manufacture of a security thread suitable for use in security articles including security paper such as that used for banknotes. In the method a magnetic metal is deposited on a film of polymeric substrate as the substrate passes through a solution containing the magnetic metal and a preparatory operation is carried out on a surface of the substrate prior to immersion of the substrate in the solution. The preparatory operation ensures that magnetic metal is deposited on the substrate in a pattern such that when the security thread is produced from the film by cutting the film the magnetic metal on the security thread has a specific pattern and provides both a visually discernible security feature and a magnetically detectable security feature.

Abstract: This invention relates to a method of making sheet materials and security paper having partially embedded therein an elongate security element which is at least substantially exposed at one surface of the sheet at a plurality of spaced locations, which method comprises the steps of depositing fibres onto a moving support surface, supplying an elongate security element to overlie rotatable embedment means, which embedment means comprise a plurality of spaced-apart raised portions having recesses therebetween, introducing the security element into the fibres with rotation of the embedment means such that some fibres move into said recesses between the security element and the embedment means so that said security element is covered by fibres, and substantially preventing fibres from penetrating between the raised portions and the overlying security element.

Abstract: Security papers according to the invention comprise opposed surfaces for the provision of printing to identify a document formed from the paper, and positioned at least partially between the two surfaces of the paper as a public security feature a security device of not more than 5 mm width, which device comprises a flexible, water-impermeable substrate with a layer of metal on one or both sides of the substrate, there being present on one side of the device a continuous metal path along its length, wherein said device has metal-free portions of between 10% and 50% of the area of the device, said metal-free portions along the length of the device providing a repeating pattern, design, indicia or the like with at least some of the metal-free portions across the tranverse direction of the device being wholly surrounded by metal. The metal-free portions may provide characters of a language, such as letters of the English alphabet.

Abstract: Apparatus for automatically inspecting brittle articles such as containers of glass and the like has element (50) which applies a force to each article in turn, so as to propagate any cracks in the glass. Ultrasonic vibrations created during the propagation of a crack is transmitted via a constant laminar stream of liquid (76) from which the vibrations are received by a transducer head (94) of the crack detection equipment, which triggers an alarm, a visual display and/or an automatic marking or rejection device.