Method and apparatus for providing security indicia on a substrate

摘要

A method of providing security indicia on a substrate comprises providing a transfer sheet comprising a carrier sheet and a releasable layer comprising a varnish layer and a layer of temperature-sensitive adhesive, the varnish layer being adjacent to the carrier sheet; producing a toner image of the indicia on the adhesive layer; positioning the transfer sheet on the substrate with the adhesive layer facing the substrate; thermally transferring to the substrate the toner image of the indicia, the adhesive layer, and the varnish layer; and removing the carrier sheet. The method is particularly useful for providing security indicia in passport books.