Abstract: A method of imaging comprising: providing a photothermographic material having at least one photothermographic medium and exposing said material to a source of narrow band radiation, wherein said material comprises one or more non-sensitizing acutance or antihalation dyes associated with said photothermographic medium providing an absorption maximum (&lgr;max) within 10 nm of the wavelength of maximum output of said narrow band source and an optical density of at least 0.05 at a wavelength (&lgr;max+50) nm.

Abstract: A thermographic element comprising in a non-aqueous binder medium a silver salt oxidizing agent in reactive association with a compound comprising a plurality of redox color releasing moieties such that oxidation of each redox color releasing moiety causes release from said compound of a thermally diffusible dye.The compounds many of which are new incorporate two or more developer moieties into a single molecule to minimize the diffusibility of the compound. Following oxidation, either directly by the silver salt or by means of a cross-oxidizing agent, each oxidized developer moiety releases a thermally diffusible dye. The compounds are of sufficient size and molecular weight to slow or prevent diffusion in imaging systems and yet possess several active developer moieties per molecule which is advantageous over known ballasted dye releasers which comprise bulky molecules with only a single developer moiety.