Incorporation of certain compounds into photothermographic materials provides materials with reduced initial image Dmin and improved Raw Stock Keeping film stability without unacceptable loss in sensitometric properties. These compounds include certain e-i) zinc salts of an aryl sulfonic acid or of a fluorinated C2-C6 carboxylic acid, e-ii) non-encapsulated alkali metal salts of an aryl sulfonic acid or of a fluorinated C2-C6 carboxylic acid, and e-iii) fluorinated C2-C6 carboxylic acids.