A printable gold precursor composed of functionalized gold nanoparticles in a suitable liquid was used for printing conductive features for organic thin-film transistors (see Figure). A thin-film conductivity of 10(5) S cm(-1) is obtained after annealing at 140degreesC under vacuum or 200degreesC in ambient conditions. Transistors using source-drain electrodes of this type provide excellent performance, identical to that using vacuum-deposited gold contacts.