Silver-free, aqueous-based direct thermographic materials are designed to have image tone with near neutral density. Without the use of organic silver salts containing reducible silver ions, the image is formed using a color developing agent precursor that releases a color developing agent when heated to a temperature of at least 80 C., a combination of cyan, yellow and magenta dye-forming color couplers that provide cyan, yellow, and magenta dyes, and a hindered-amine N-oxyl as an oxidizing agent. No silver metal or silver ions are purposely added to these materials. This combination of components provides a means for controlling image tone without reliance upon conventional toning agents.