Fish gelatin, on the other hand, has a lower gel strength and gelation temperature due to the lower content of proline and hydroxyproline, making it a more flexible and easily manipulated matrix under ambient conditions. Its relatively lower viscosity enables it to serve as a continuous phase in the composite, maintaining fluidity until photo-crosslinking is initiated. Fish gelatin's characteristics thus complement the rigidity of porcine gelatin, creating a composite hydrogel with both mechanical stability and processability for extrusion and DLP printing. The blend of these two gelatin types provides a tunable system where porcine gelatin microparticles reinforce the structure, while the fish gelatin matrix maintains the composite's printability and photoreactivity.