First, small amplitude oscillatory strain measurements were carried out at 22 °C for gelled GelMA solutions (its optimal temperature for extrusion-based printing) to determine the printability window in shear moduli (storage modulus 𝐺′: 20-700 Pa). Then, 5 wt% of a low-viscosity GelMA solution at 37 °C was supplemented with increasing amounts of either DbPEs or TbPEs to obtain formulations whose moduli were within the printability moduli window. Both DbPEs and TbPEs represented suitable ink additives; their addition resulted in an immediate increase in the shear moduli of the hybrid inks (Figure ). However, the respective quantities of DbPEs and TbPEs required to achieve ink formulations with moduli within the printability window were very different, ascribable to the different PEC microstructures (jammed micelles vs. interconnected networks) they form. For TbPEs, even small concentrations (𝐶 !"#$ ≤ 10 wt%) had a significant impact on the ink moduli, while DbPE concentrations 𝐶 %"#$ ≥ 20 wt% were required to achieve moduli commensurate to printable inks.