The influence of hydrostatic pressure (P) up to 200 bar of gaseous He was investigated on holes burned over the inhomogeneous S-1 <-- S-0 absorption bands of polycyclic hydrocarbons, a polymethine dye, and tetrapyrrolic compounds imbedded in polymer matrices. The pressure shift coefficients d nu/dP show a linear dependence on hole burning frequency (nu) that can be extrapolated to the frequency nu(0(P)), where no pressure shift occurs. The nu(0(p)), values deviate significantly from the actual 0-0 origins of the nonsolvated chromophores. The dependence of d nu/dP on nu can be considerably steeper than the 2-fold isothermal compressibility of the matrix 2 beta(T), expected for the distance dependence of intermolecular potential r(-6) (e.g. London forces). Other solvent shift mechanisms, such as linear and quadratic Stark effects in the matrix,cavity field, yield lower slope values than 2 beta(T) (1/3 beta(T) and 2/3 beta(T), respectively). Tentatively, these controversies are rationalized in terms of intermolecular repulsive interactions that have a much steeper distance dependence (r(-12)) than the electrostatic or dispersive forces. The solvent shifts of band maxima, the inhomogeneous bandwidths, and the pressure shifts of spectral holes are discussed in terms of intermolecular interaction mechanisms.