| 摘要 |
Linerless postage stamps are produced by coating a paper substrate on the bottom surface with pressure sensitive adhesive, and coating the substrate on the top surface with release material, such as silicone, which includes an effective amount of stamp cancellation ink retaining particles, so that when the release coat and particles are contacted by stamp cancellation ink the particles will retain sufficient stamp cancellation ink so that the ink is visible on the top face and will not be wiped off during normal handling. The particles may comprise fumed silica, colloidal silica, kaolin clay, aluminum oxide, wollastonite, talc, calcium carbonate, titanium dioxide, or combinations thereof. Stamp indicia is typically provided on the top of the substrate underneath the release coat. |
