and negative (2000 µm length) features with decreasing width (500 to 100 µm length) was designed. Inks were prepared as described before. The CAD model was loaded into the software of the printer, sliced and the printing platform was calibrated. A coverslip with 24 mm diameter was semi-permanently fixed on the printing platform using a photocurable PEG diacrylate ink. The ink was loaded into the ink reservoir, the printing platform lowered into the ink and the designated construct printed. The model consisted of one layer (1000 µm layer height) with a length of 13.5 mm and width of 4 mm. After printing, the scaffold was carefully washed with PBS to remove uncured ink, detached from the printing platform, and imaged with a microscope (Leica DMi1,