Molecularly doped polymers processed by dye-diffusion thermal transfer (D2T2) have wide applications in electronic imaging. For the sake of stability, it is usually desired that the host polymers have high glass-transition temperatures (Tg), which however implies high processing temperatures. In this letter, we show that in an atmosphere of organic solvent vapor, effective dye-diffusion thermal transfer may be carried out at temperatures much below the Tg of a host polymer. The atmosphere of solvent vapor ensures incorporation of solvent molecules into the polymer throughout the process and causes the plasticization effect. As a consequence, the effective Tg of the system is lowered and the diffusion of dyes in the host polymer is enhanced. Through such a process, polymers of higher Tg and wider ranges of dye molecules may be used in D2T2 without losing the processing compatibility. Furthermore, carrying out D2T2 at lower temperatures is beneficial to the resolutions of transferred features due to the suppression of vaporization of dyes. © 2002 American Institute of Physics.