Carbonless coating compositions which can be printed onto one or more sheets of a business form or mailer to provide a visible image which is sharper and darker than previous coatings are provided. The compositions also find use on security documents and safety papers to provide a covert image on the document beneath information which may be subject to attempted alteration, such as the amount written on a check. The covert image becomes visible upon the application of pressure or solvent in the area coated to provide evidence of the attempted alteration. The self-contained composition includes an admixture of a color former, a color developer, and a plurality of pressure-rupturable microcapsules containing a solvent. Another solvent-sensitive composition includes an admixture of a color former and a color developer.