An ink for solvent-cast 3D printing is provided. The ink comprises a solution or gel of a polymer in a volatile solvent, and carbon nanotubes dispersed in the solution or gel. In the ink, the carbon nanotubes are present in a carbon nanotubes:polymer weight ratio between about 20:80 and about 40:60, and the polymer and carbon nanotubes total concentration is between about 20 and about 35 wt %, based on the total weight of the ink. There is also provided a 3D printer ink cartridge comprising the ink; a method of manufacturing the ink; a method of manufacturing a solvent-cast 3D printed material using the ink, a solvent-cast 3D printed material as well as uses thereof.