The need to provide realistic boundary data in elastic contact problems is emphasized and a new theory developed to model “soft” elastic contact in colloid science, when the elastic bodies distort under a surface interaction without physical contact occurring. For a given interaction the surface displacement is determined by a nonlinear integral equation. Bounds on the surface displacement are exhibited for a wide class of attractive and repulsive interactions. For a strong, short-range interaction it appears that the model yields similar results to those of the classical theory of Hertz.