I search the New York Times and I found in the past year 111 results for "3D" and 903 results for "3-D".
But I'm not sure if there's any rhyme or reason to whether that newspaper uses one or the other; they say "3D-printed", but that's a special case that's not relevant to my own situation because I'm just saying "the normal 3-D arrangement" and "the antler rack’s 3-D structure".
1: Do you guys see any pattern, or is it just random?
2: And should I just go with "3-D"? That's what I've done for the time being.