The Daily Dot has posted their interview with Luca Mosca, the costume designer for John Wick: Chapter 2. Mr. Mosca discusses the ins and outs of designing the costumes for the various characters in the film. When ask specifically about the design process for Keanu, he said the following:
We should start with saying that with the elegant and regal posture of Keanu Reeves, shaping a beautifully tailored suit on him is an easy task. We wanted a clean line, we wanted it close to the body and we obviously had to give it functionality. He needed a lot of movement in order to perform all these stunts.
It was about the choice of color first, which is a colorless choice. John Wick’s costumes can basically been seen in a color film or in a black and white film. And we spent countless fittings trying to perfect those shoulders and the proportion of the pants, slimming them by millimeters at a time.
In John Wick 2, we enhanced these regal aspects of Keanu Reeves, we increased the proportion of the collars in the shirts, almost like a Napoleonic reference, so that the face is framed and the posture is almost forced to be more elevated and more erect.
You can read the entire intrview at the link above. It was a good read. As an aside, Mr. Mosca also played the tailor in the film and has caught the acting bug. He has been taking drama classes and has appeared in a play in NYC.