Optically pumped magnetometers (OPMs) are a promising magnetoencephalography (MEG) technology for the non-invasive measurement of human electrophysiological signals. Prior work developed biplanar background field-nulling coils necessary for OPM operation, but these were expensive to produce and required tedious error-prone manual winding of >
1 km of copper wire. Here, we developed a precise and reproducible manufacturing process by fabricating these coils on two-layer printed circuit boards (PCBs). Building on open-source software (bfieldtools), we developed a pipeline to determine the optimal current loops of 1.5 × 1.5 m