Amorphous-silicon (a-Si) thin-film transistors (TFTs) were fabricated on a free-standing new clear plastic substrate with high glass transition temperature (T_g) of >315° C and low coefficient of thermal expansion of <10 ppm/ ° C. Maximum process temperatures on the substrates were 250°C and 280°C, close to the temperatures used in industrial a-Si TFT production on glass substrates. The first TFTs made at 280°C have dc characteristics comparable to TFTs made on glass. The stability of the 250°C TFTs on clear plastic is approaching that of TFTs made on glass at 300°C-350°C. TFT characteristics and stability depend only on process temperature and not on substrate type.