What should I wear the day I get a tattoo on my back?

I'm a chick getting a large-ish tattoo on the upper left quadrant of my back (shoulder blade) in a few days. It's my first, and for now my "last." I've been saving up for a long time to get it done at a very nice place. I'm just unfamiliar with the etiquette with getting body art in different locations. Should I try to find a halter dress or top that reveals enough of my back for the tattoo to be placed? Should I wear something that I'm not worried about getting stained by ink? Or is it okay to just take something easy to remove and hold a sweater or blanket to my chest during the session? I'm not shy by any means, but the studio I'm going to appears to be open (I'm sure there are probably private rooms, though I didn't see them, nor did I request one) and I don't want to give my artist a heart attack by ripping my top off (though I had a friend who did that and apparently her artist thought it was pretty funny after he recovered from the shock). I've already met my artist, and he knows the design and location.