Ion traps are central to one of the most promising approaches in quantum computing. Until now, scaling up ion traps has been tricky. Because the surfaces of ion traps are a major source of error, 3D printing may allow researchers to remove unnecessary material and improve performance. Miniaturized ion traps could be used in precision sensors, advanced atomic clocks, or compact mass spectrometers. By showing what high-resolution 3D printing can achieve, the work may also inspire new applications across science and technology.