Corrected entry: When we first see Wolverine, his sideburns are thick and full, but when he wakes up in Xavier's school, his sideburns are not nearly that thick, in fact, they look rather scrubby. They change back to thick at the end of the movie, when Logan puts on the X-men uniform. (00:22:10)
Bruce Minnick
21st Mar 2002
Correction: They used the same make-up/hair pieces for Wolverine through the whole movie. The variations in thickness are an optical illusion, based on the lighting conditions (more light makes them look thinner, less light makes them look thicker).
Bruce Minnick