3D printing was performed using a digital light processing printer at a vat temperature of 105 °C and using an LED with its emission maximum centered around 385 nm (Supplementary Figure ). 50 µm thick layers were exposed for 11 s each with an irradiation intensity of 25 mW cm -2 . The vat was coated with formulation for each layer by simply moving the building platform upwards and back down into printing position.