Bank notes, bonds and other instruments of value

摘要

Banknotes, bonds, &c. are made from a flexible sheet of a non-inflammable water-resistant plastic material, such as a plasticized polyvinyl ester resin or polyvinyl butyral, provided with depressions in the shape of the indicating numbers or figures, the depressions being filled with a flexible material of another colour than the material of the sheet. The numbers may be formed by embossing a single sheet 11, Figs. 1 and 2, the depressions 12 being then filled with a plastic material 14 of another colour, or with printing-ink &c. A covering-sheet 16, Fig. 3, may be attached by cementing or fusing. Two outer sheets of stretchable material may be combined with an inner sheet, which is flexible but not stretchable, in order to maintain the shape. The inner sheet may be opaque and covered by transparent outer sheets, or one of the outer sheets may have transparent patches. The sheets may, in addition, contain a fluorescent or phosphorescent substance, or one which is absorbent or reflective of ultra-violet or infra-red rays, or they may be given a polarizing effect by stretching. The sheets may embody a watermark-like pattern, embedded fibres, or liquid or gas bubbles. Additional marks, such as punched holes, toothed edges, or roughened surface portions, may be provided to facilitate sorting or counting. The Specification as open to inspection under Sect. 91 comprises also the production of banknotes by weaving from filaments of the plastic material, the indicating-numbers being incorporated in the fabric. This subject-matter does not appear in the Specification as accepted.