20 Things You Didn't Know About Star Trek: First Contact
17. The Borg Were Given A Big-Budget Redesign
Budgetary constraints meant that the crew of The Next Generation weren't totally happy with how the Borg looked on the show, but First Contact's beefier budget allowed them to take the intended design much further, and retain the costumes and sets for later use on Star Trek: Voyager.
The makeup team's process for Borg actors on the movie took five times as long compared to The Next Generation, as they opted for a more visceral and involved look that better conveyed how thoroughly an assimilated person is subsumed by the Borg.
The crew also created variations between Borg members, with some of them being assimilated aliens such as Klingons, Romulans, and so on, to further the story of the Borg's conquest in a subtle but vital way.
Once shooting was complete for the day, it reportedly took a Borg actor two hours to get out of the elaborate costume and remove all their makeup.