It　is　well-known　that　tissue　engineering　scaffolds　that　feature　highly　interconnected　and　size-adjustable　micropores　are　oftentimes　desired　to　promote　cellular　viability,　motility,　and　functions.　Unfortunately,　the　ability　of　precise　control　over　the　microporous　structures　within　bioinks　in　a　cytocompatible　manner　for　applications　in　3D　bioprinting　is　generally　lacking,　until　a　method　of　micropore-forming　bioink　based　on　gelatin　methacryloyl　(GelMA)　was　reported　recently.　This　bioink　took　advantage　of　the　unique　aqueous　two-phase　emulsion　(ATPE)　system,　where　poly(ethylene　oxide)　(PEO)　droplets　are　utilized　as　the　porogen.　Considering　the　limitations　associated　with　this　very　initial　demonstration,　this　article　has　furthered　the　understanding　of　the　micropore-forming　GelMA　bioinks　by　conducting　a　systematic　investigation　into　the　additional　GelMA　types　(porcine　and　fish,　different　methacryloyl-modification　degrees)　and　porogen　types　(PEO,　poly(vinyl　alcohol),　and　dextran),　as　well　as　the　effects　of　the　porogen　concentrations　and　molecular　weights　on　the　properties　of　the　GelMA-based　ATPE　bioink　system.　This　article　exemplifies　not　only　the　significantly　wider　range　of　micropore　sizes　achievable　and　better　emulsion　stability,　but　also　the　improved　suitability　for　both　extrusion　and　digital　light　processing　bioprinting　with　favorable　cellular　responses.