Patent ID: 6879805

Claim:
A test answer form comprising: a substrate having top and bottom surfaces; chromogenic material applied to at least a top surface portion of said substrate, said chromogenic material being adapted to irreversibly generate a visible change in color in a selected area, upon exposure of the area to an activating agent; a plurality of answer spaces printed on said chromogenic material, said plurality of answers spaces being arranged in X rows and Y columns, with each row being associated with a particular question, and each column with a possible answer choice wherein said chromogenic material can be activated by the activating agent to provide desired indicia in selected areas; and a removable opaque layer overlaying at least a surface portion of the chromogenic material at each location of said plurality of answer spaces on said substrate, said opaque layer being present during application of said activating agent to conceal the indicia generated in said chromogenic material associated with the corresponding answer spaces.