1. A thermal image generator comprising: (a) a support structure with a top surface; (b) first and second foil layers positioned side-by-side on the top surface of the support structure with a vertical gap between them; (c) a heat grid situated directly on top of the first and second foil layers that is comprised of a plurality of horizontal wires and vertical wires that span nearly the entire top surface of the support structure; (d) wherein the heat grid has outer edges, an interface layer between the heat grid and the first and second foil layers that does not reach to the outer edges of the heat grid, thereby allowing the outer edges of the heat grid to touch the first and second foil; (e) connector strips that run along the outer edges of the heat grid and that form a connection between the heat grid and the first and second foils; (f) wherein the heat grid has a top surface, an image layer that is adhered directly onto the top surface of the heat grid; and (g) a voltage in power lead crimped to the first foil and a voltage out power lead crimped to the second foil; wherein the heat grid has an outline, and the first and second foil layers are oriented to follow the outline of the heat grid; and wherein horizontal wires of the heat grid provide heat-generating voltage, and the vertical wires provide an alternative electrical path if a horizontal wire is broken.