Commercial PDMS screening: Commercially available acrylated PDMS products were screened by mixing 200 mg of the corresponding acrylated PDMS, 49.3 µL of trioctylamine and 4.0 mg of 2isopropylthioxanthone. The mixture was sonicated at 50°C for 30 minutes or until homogenous mixture was obtained. The formulations were then applied on functionalized coverslips and printing attempts with different printing parameters were performed using the specified 2PLP procedure. Formulations from commercially available PDMS sources that showed potential printability were further optimized.