A novel strategy via paper as an effective substrate has been introduced as a thermoelectric material in this work. Free-standing poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/paper composite films are conveniently prepared by a one-step method of directly writing PEDOT:PSS solution on paper, making the process simple, rapid, and facile. The free-standing composite films display excellent flexibility, light weight, soaking stability in water, and great potential in large-scale production. Improved thermoelectric properties are obtained in PEDOT:PSS/paper composite films, owing to the simultaneously enhanced Seebeck coefficient (30.6 V K-1) and electrical conductivity, and a low thermal conductivity (0.16 W m(-1) K-1) compared with pristine PEDOT:PSS films. The results indicate that paper as an effective substrate is suitable for the preparation of high-performance and flexible thermoelectric materials. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 737-742