As of my last knowledge update in September 2021, printed supercapacitors typically have voltage ratings in the range of a few volts to tens of volts. The exact voltage rating can vary depending on the specific design, materials, and manufacturing processes used in the printed supercapacitor.
It's important to note that advancements in technology and research could have led to changes or improvements in printed supercapacitor designs since then. I recommend checking with current sources or manufacturers for the most up-to-date information on the voltage ratings of printed supercapacitors.