The rapid development of portable electronics has put great demand on flexible energy-storage devices, such as solid-state supercapacitors (SCs). However, the scalable fabrication of flexible SCs is still an issue. Herein, a simple and low-temperature route for the scalable fabrication of flexible SCs is presented. First, a printable process is developed to fabricate a carbon film electrode on graphite paper, which serves as the anode. Then, the cathode is fabricated by electrodepositing MnO2 on the carbon film. Utilizing LiCl/polyvinyl alcohol (PVA) as a solid-state electrolyte, the assembled device exhibits excellent electrochemical performance even in a bent state or under high-temperature conditions. The operating voltage of the device is extended to 2.0 V. An energy density of 0.766 mWh cm−3, 91.4 % retention of the initial capacitance after 4000 cycles, and stable capacitive behavior at different bent angles can be achieved. At 60 °C, 97.7 % of the initial capacitance is retained after 2000 cycles. This printable process with simple, low-costing, and low-temperature features holds promise for applications in the scalable fabrication of flexible carbon-based SCs.