We have modified the conventional arc discharge method for the synthesis of high quality single-walled carbon nanotube (SWNT) silks with high purity (over 70%) by using a hollow cathode that can collect SWNTs effectively. Characterizations of these SWNT materials by XRD, UV-vis-near-IR, Raman were taken. Finally a simple process involving subsequent acid treatment to align the SWNTs locally in the thin silks was introduced.