A security sheet

A security sheet (11, Fig.1) comprises a data sheet (15, Fig.1) for displaying data and an attachment layer 17. The attachment layer comprises a plurality of tabs 25 extending from an attachment portion 26 for attaching the data sheet into a security document (10, Fig.1)​. The plurality of tabs are attached to the data sheet such that the attachment layer is attached to and extends from the data sheet. The data sheet is formed from at least a plurality of body layers 18 and at least one tab of the plurality of tabs is attached between two adjacent body layers attached to one another. The attachment layer can comprise a textile wherein the attachment portion comprises a plurality of warps (30, Fig.3) intersecting a plurality of wefts (31, Fig.3) and the plurality of tabs comprises portions of the plurality of warps extending from the plurality of wefts. There is also disclosed a method of forming the security sheet.