What a brand book contains

A brand book exists so the brand looks the same no matter who happens to be making the material. Without it, after a year a company has four shades of its own colour and three different versions of the logo, each from a different contractor.

The two most important and most often skipped parts are the clear space, meaning how much empty room has to stay around the mark, and the section on mistakes, meaning what must never be done with the logo. In practice those are what save a brand.

A full brand book is not a condition for launching a website. It often comes later, built on what proved itself in real use.