Abstract: This invention relates to paper, or like sheet material, having a coating comprising minute, liquid-containing, pressure-rupturable capsules, and also larger, non-rupturable kaolin-containing stilt capsules arranged in interspersion and in close juxtaposition. In the preferred embodiment the smaller capsules contain a liquid marking agent. The capsules, large and small, are interspersed as to size, and are closely spaced on the sheet, so that an intentional impact directed on a small area of the coating will crush substantially all of the small capsules in the area and result in the release of liquid marking agent, whereas a casually applied pressure will rupture relatively few of the small capsules in the area. The marking liquid may be a colorless chromogenic color reactant. The small capsules on a sheet containing said marking liquid may be associated with other color forming materials on said sheet, or alternatively said color forming materials may be contained on another contacting sheet.