The THz spectra are measured after (i) the samples were vacuum dried at 40 C for 1 week, (ii) the samples were stored in the hydration chamber for 1 week, and (iii) after the samples were vacuum dried again at 40 C for 1 week. The humidity of the hydration chamber was controlled by a saturated solution of (a) KCOOCH3 (22 %RH) and (b) NaCl (76 %RH), respectively. The initial spectra (i) show no absorption bands at 6.5 THz, and shows a similar spectral shape as nylon-6, as observed in our previous stidues. The THz spectra clearly show that our sample preparation results in nylon-6 films containing both amorphous and -crystalline structures.