Abstract: Structures for items such as promotional materials, game pieces, lottery tickets, security documents and other articles, which feature one or more thermal reactive layers that are activated by heat from a hidden image formed of infrared sensitive, heat generating material such as carbon black preprinted under the thermal reactive layers during manufacture. The thermal reactive layers permit transmission of radiant energy such as infrared to the heat generating, hidden layers. The heated image conducts heat to the thermal reactive layers which employ a coloring agent and a developer which, when exposed to the heat, react or act in concert in order to form a corresponding image on the face of the item.