These fabric caps are sturdy enough to hold not only EEG electrodes in place, but also NIRS optodes, e.g. from NIRx, Hitachi and Artinis. It is possible to record EEG and NIRS simultaneously by placing electrodes and optodes into the same cap.
We can create caps from black fabric with openings for optode-grids according to the specification of the user. In some situations we can also supply the respective holders, and of course we can contribute the electrodes for simultaneous recordings.
While in the early years of NIRS, fixed inter-optodes distances had been required, this belief seems to have changed. This means that caps with openings according to 10%-system allow for temporary grids, whether they are frontal, lateral, parietal, or over certain brain areas (e.g. Broca/Wernicke) and then move the optode holders to other openings for the next experiment.