To determine the minimum exposure time for each ink, we first printed 3-layers discs with a diameter of 6-9 mm and a layer thickness of 1 mm with the HA-X hydrogels. The exposure time per layer was increased between 1 and 50 s. The resulting discs were imaged and their dimensions and the contours were compared. Figure shows representative images of HA-X scaffolds printed with different exposure times.