Per epoch GRAVITY spectra (in color, scaled according to the last column of the observations table on Zenodo) and the final combined spectrum (black) for all 39 substellar companions in the ExoGRAVITY Spectral Library. The N epochs are sorted chronologically, starting with the oldest, using the following color palette: blue = 1, orange = 2, green = 3, red = 4, purple = 5, brown = 6, pink = 7, gray = 8, olive = 9.