The invention relates to equipment such as for detecting and providing visual confirmation of pressure thereon, e.g. from an impact, which comprises an article having a sandwich construction with a pressure-disclosing layer (3) comprising a liquid crystal, thermochromic material, and a temperature differential layer (5), separated by a layer (4) providing a compressible mechanical shield between the pressure-disclosing layer and the temperature-differential layer. Material according to the invention can be employed to indicate the boundaries of a tennis court, or sports playing areas, or as a golf training aid, among other uses.