What makes a quality hat?

Most hats are today are poor quality. Often in wool, they're not built to last or be repaired. So what makes a quality hat? Is it just the felt, or the machinery, the ageing? Simon Crompton of Permanent Style quizzes master hatmaker Graham Thompson - who runs Optimo hats in Chicago - to get to the details. Also, find out which style of hat might suit you, and why a 10-gallon hat could suit anyone, if they have the right style... The interview takes place in front of an audience of Permanent Style readers and Optimo customers, on Savile Row in London.