Hi Pdspecl
For labeling tubes I just grab a sharpie like what Rodman states and write carefully on the glass itself where I won't touch them frequently. For 6SN7 type tubes I would put a small label on the base.
Check out the Brent Jessee videos on how to identify various rare 12AX7 and 12AU7 type tubes.
https://www.youtube.com/watch?feature=player_embedded&v=_6d-cZB7DgA
https://www.youtube.com/watch?v=EisjVc5yIj4
For labeling tubes I just grab a sharpie like what Rodman states and write carefully on the glass itself where I won't touch them frequently. For 6SN7 type tubes I would put a small label on the base.
Check out the Brent Jessee videos on how to identify various rare 12AX7 and 12AU7 type tubes.
https://www.youtube.com/watch?feature=player_embedded&v=_6d-cZB7DgA
https://www.youtube.com/watch?v=EisjVc5yIj4