Provided are a bioink including a collagen fiber with an average fiber length of from 0.5 to 1,000 μm, a shaped object printed with the bioink, a product, and a method for producing a shaped object. The bioink is characterized by including a collagen fiber composed of collagen and/or a collagen derivative and a solvent, the collagen fiber having an average fiber length of from 0.5 to 1,000 μm. The bioink can be extruded from a 3D printer even with a collagen fiber concentration of from 5 to 30% (w/w). The shaped object obtained by bioprinting is excellent in terms of resolution, thermal stability, and structural stability.