LIRIS (red dots) and NIRSPEC (black line) spectra of Pleiades proper motion candidates. The NIRSPEC spectrum of Calar 21 is normalized to the K-band LIRIS spectrum. The left panel illustrates the comparison of the Pleiades data with field, high-gravity dwarfs, and the right panel highlights the comparison with young (low-gravity) sources. The reference spectra (blue and gray lines) correspond to 2MASS J22244381−0158521 (L4.5, LIRIS data), DENIS J122815.2−154733 (L6), and SDSS J042348.57−041403.5 (T0) in the left panel, and to G 196-3B (L3), 2MASS J00452143+1634446 (L2, LIRIS data), 2MASS J03552327+1133437 (L5, LIRIS data), and 2MASS J12073347−3932540b (L7) in the right panel. To improve the quality of the Pleiades data, the following binning factors (in pixels) were applied: 25 (ZJ) and 29 (HK) for Calar 16, 35 (ZJ) for Calar 18 and 19, 44 (ZJ) and 51 (HK) for Calar 20, 41 (HK) for Calar 21, and 55 (HK) for Calar 22. The vertical error bars of the red dots stand for the errors of the mean fluxes, and the horizontal bars account for the wavelength coverages of the binning intervals. For clarity, regions of strong telluric absorption were intentionally removed from the LIRIS and NIRSPEC spectra, and the data normalized to 1.0 at around 1.3 or 1.68 μm and shifted by a constant.