SECURITY DOCUMENTS

摘要

A substantially non-translucent security document comprises a pair of sheet (1, 2) substantially non-absorbent of X-rays and beta radiation between which sheets is located a security device (4) substantially absorbent of X-rays and beta radiation and detectable upon inspection of the security document by X-rays and beta radiation. The sheets (1, 2) are secured together by adhesive (3) and encapsulated in transparent sheets (5).