Abstract: To prevent the formation of scratches, surface discontinuities, slide tracks or striations, for example due to sliding of electrodes (20) over the metal layer (12) of a metalized recording medium, a protective surface coating (13) of low-friction sliding protective material is applied in the form of discontinuous islands over the metal layer (12). The discontinuities permit electrical contact between the electrode (20) and the metal layer (12) although the protective surface coating (13) has insulating properties. The coating (13) may be polymerized hexamethyl-disiloxane, hexafluoropropylene, or Teflon, polymerized, preferably in a hot cathode glow discharge; or a metallic soap. The protective layer is hydrophobic in the form of islands of a thickness of between 10.sup.-9 m to 10.sup.-7 m, preferably about 1 to 2.times.10.sup.-8 m, thus protecting the underlying metal layer (12) against damage by the electrode (20), and attack by moisture or dampness from the ambient atmosphere.

Abstract: To reduce adherence of particles to electrodes and improve the contrast of recording paper, particles of oversized pigments are including in a contrast lacquer or ink layer which have a diameter such that the oversized particles or grains extend out from the lacquer or contrast layer, that is, have a diameter which is greater than the thickness of the ink layer. Suitable particles are carbon black, and calcium carbonate, particularly if darkly colored, present in about 3%-by weight-of the wet content of the lacquer layer which, for example, is a layer of nitrocellulose with finely grained carbon black pigment therein, of a thickness in the order of 1 to 10 .mu.m; the additional oversized pigment granules will have a thickness in the order of about 2 to 20 .mu.m, preferably, on the average, about 5 .mu.m and embedded in lacquer layer of about 2 .mu.m thickness, over which a vapor deposited layer of aluminum of between 0.01 and 0.1 .mu.m is applied. A typical substrate is paper.

Abstract: To prevent the formation of scratches, surface discontinuities, slide tracks or striations, for example due to sliding of electrodes (20) over the metal layer (12) of a metalized recording medium, a protective surface coating (13) of low-friction sliding protective material is applied in the form of discontinuous islands over the metal layer (12). The discontinuities permit electrical contact between the electrode (20) and the metal layer (12) although the protective surface coating (13) has insulating properties. The coating (13) may be polymerized hexamethyl-disiloxane, hexafluoropropylene, or Teflon, polymerized, preferably in hot cathode glow discharge; or a metallic soap. The protective layer is hydrophobic in the form of islands of a thickness of between 10.sup.-9 m to 10.sup.-7 m, preferably about 1 to 2.times.10.sup.-8 m, thus protecting the underlying metal layer (12) against damage by the electrode (20), and attack by moisture or dampness from the ambient atmosphere.