When Bogart played the role of Sam Spade, he set the bar for all gumshoes to come. Also it defined the look and feel of the characters that audiences loved him to play and the roles he would be remembered for.
A big part of the character was Spade's long coat and fedora. Unlike Bogart's Rick Blane in Casablance, Spade wears his hat a lot. He is never without it. It is easy to understand.
That is one fine lid.