Strippable layer frost printing

Claim 1

A METHOD OF XEROGRAPHICALLY FORMING AN IMAGE PATTERN OF CONTINUOUS TONE AREAS OF A DEFORMABLE SURFACE COMPRISING: (A) PRODUCING A SELF SUPPORTING PLASTIC LAYER BY COATING A 1/4- TO 2-MIL THICK POLYETHYLENE TEREPHTHALATE SHEET WITH A THERMOPLASTIC FILM READILY DEFORMABLE AT TEMPERATURES BELOW ABOUT 150*F., (B) WIPING A XEROGRAPHIC PLATE HAVING AN INSULATING PHOTOCONDUCTIVE LAYER ADHERENT TO AN ELECTRICALLY CONDUCTIVE SUBSTRATE WITH A LOW VISCOSITY ELECTRICALLY INSULATING OIL APPLIED TO THE PHOTOCONDUCTIVE LAYER, (C) ELECTROSTATICALLY CHARGING SAID INSULATING PHOTOCONDUCTIVE LAYER WITH RESPECT TO SAID SUBSTRATE, (D) APPLYING SAID SELF SUPPORTING PLASTIC LAYER OVER SAID XEROGRAPHIC PLATE, WITH SAID SHEET ADJACENT SAID INSULATING PHOTOCONDUCTIVE LAYER, (E) EXPOSING SAID XEROGRAPHIC PLATE IN AN IMAGE PATTERN OF LIGHT AND SHADOW, (F) SOFTENING SAID THERMOPLASTIC FILM UNTIL A CONTINUOUS TONE DEFORMATION IMAGE PATTERN APPEARS AT THE SURFACE OF SAID FILM, CORRESPONDING TO SAID IMAGE PATTERN OF LIGHT AND SHADOW, SAID DEFORMATION PATTERN BEING CHARACTERIZED BY ALTERNATING ELEVATIONS AND DEPRESSIONS RANDOMLY POSITIONED WITH RESPECT TO SAID FILM SURFACE AND HAVING A LATERAL SPACING OF 1-5 TIMES THE THICKNESS OF SAID FILM, AND (G) SEPARATING SAID SELF SUPPORTING PLASTIC LAYER WITH SAID DEFORMATION PATTERN FROM SAID XEROGRAPHIC PLATE.

Claim 2

A METHOD OF XEROGRAPHICALLY FORMING AN IMAGE PATTERN OF CONTINUOUS TONE AREAS OF A DEFORMABLE SURFACE COMPRISING: (A) PRODUCING A SELF SUPPORTING PLASTIC LAYER BY COATING A 1/4- TO 2-MIL THICK POLYETHYLENE TEREPHTHALATE SHEET WITH A THERMOPLASTIC FILM READILY DEFORMABLE AT TEMPERATURES BELOW ABOUT 150*F., (B) WIPING A XEROGRAPHIC PLATE HAVING AN INSULATING PHOTOCONDUCTIVE LAYER ADHERENT TO AN ELECTRICALLY CONDUCTIVE SUBSTRATE WITH A LOW VISCOSITY ELECTRICALLY INSULATING OIL APPLIED TO THE PHOTOCONDUCTIVE LAYER, (C) ELECTROSTATICALLY CHARGING SAID INSULATING PHOTOCONDUCTIVE LAYER WITH RESPECT TO SAID SUBSTRATE, (D) APPLYING SAID SELF SUPPORTING PLASTIC LAYER OVER SAID XEROGRAPHIC PLATE, WITH SAID SHEET ADJACENT SAID INSULATING PHOTOCONDUCTIVE LAYER, (E) EXPOSING SAID XEROGRAPHIC PLATE IN AN IMAGE PATTERN OF LIGHT AND SHADOW, (F) SOFTENING SAID THERMOPLASTIC FILM UNTIL A CONTINUOUS TONE DEFORMATION IMAGE PATTERN APPEARS AT THE SURFACE OF SAID FILM, CORRESPONDING TO SAID IMAGE PATTERN OF LIGHT AND SHADOW, SAID DEFORMATION PATTERN BEING CHARACTERIZED BY ALTERNATING ELEVATIONS AND DEPRESSIONS RANDOMLY POSITIONED WITH RESPECT TO SAID FILM SURFACE AND HAVING A LATERAL SPACING OF 1-5 TIMES THE THICKNESS OF SAID FILM, AND (G) SEPARATING SAID SELF SUPPORTING PLASTIC LAYER WITH SAID DEFORMATION PATTERN FROM SAID XEROGRAPHIC PLATE.