Sheet materials

A method for making a sheet of paper for security documents by drawing fibres from a liquid suspension of fibres through a forming support surface and depositing them onto said forming support surface which method comprises disposing a continuous elongate security element on the forming support surface which forming support surface is modified so that as fibres are drawn from the suspension onto the forming support surface the elongate security element becomes generally incorporated in the sheet but is left at least substantially exposed at at least one surface of the sheet at a plurality of spaced locations wherein the modified forming support surface has portions which are raised relative to adjacent areas of the surface, and the elongate element is disposed to extend over the raised portions, the deposition of fibres being in such a manner that substantially no fibres are deposited between the raised portions and the overlying elongate element, whereby the elongate element becomes generally disposed within the thickness of the sheet formed by the deposited fibres but at least substantially exposed at least one surface of the sheet at a plurality of spaced locations.