The effect of a number of dyes on the glass transition temperatures of a variety of polymers has been investigated. The glass transition temperatures of each dye-polymer blend were compared to the Kwei equation to obtain Kwei q parameters. It was demonstrated that the q parameter correlated to dye-polymer interaction independent of the variation in dye structure and polymer composition. The highest q parameters were obtained as the solubility parameters of dye and polymer approached corresponding to the maximum dye-polymer affinity.