Abstract: A transparent, tamperproof seal which is utilized for the protection of signed texts and documents. The tamperproof transparent seal for signed texts or documents, inclusive of checks, is constituted of at least one card having on one side thereof, an adhesive inking and varnishing multilayer lamina which is at least partially transparent, and with a suitable movable sheet-like carrier or substrate consisting of a transparent plastic material; and on the other side, possessing a delayed-action adhesive selected from a group of pressure-sensitive adhesives, and which is protected by a liner, heat-activated adhesives and wet-activated adhesives.

Abstract: A case of plastic material for at least one marketable valuable piece as a coin, a medal, a precious stone, a pearl, a stamp or the like, including two superimposed elements, at least one of which is transparent and formed with a shell to lodge the piece. The elements are connected at least along their edges, and between the upper and lower elements which enclose the piece with certification data, a tamperproof seal is provided against counterfeiting and against forced opening. The seal includes a delaminable security printing pattern in the form of a hologram or of a multi-ink layer which is discontinuously adhered so as to be visibly and irreparably lacerated upon an opening attempt being imparted to the case.

Abstract: On a printing substrate an inking interlaced multilayer is coated which incorporates a latent configuration to be rendered visible as an actual irreversible image at any later moment by its transposal onto a new support, the obtained product being applicable as a protection against counterfeiting on commercial articles, packings, for publishing, advertising, certification purposes and so on. FIG. 6 shows an active label-seal in which the latent disc-shaped configuration is transposed from the printing substrate on the packing 12 provided as support, when the label-seal 13 is separated in stripping from said packing 12 off the closure line 14. FIG.