Michael Bierut tells it like it is

New York Times Building Signage

Michael Bierut’s 2009 presentation from The 99% where he brings to light five secrets contained within the 86 notebooks he’s kept over the course of his career is worth the watch regardless of your profession. Discussed within, among other pieces, is how he arrived at the solution for the signage on the New York Times Building pictured above.

I also recommend reading his book 79 Short Essays on Design.