and so, in order to communicate it, you just needed one thin slice of it which lets you see the relationship between these thin triangles and a complete dome. the eighth part of the exhibition is devoted to royal patronage. what you see first is the section on robes of honour. they've been a huge motor for the production of luxury textiles in iran. in order to be a proper ruler, the ruler had to have very large stocks of luxury textiles. because it was the custom that, when people came to court — such as an ambassador or a vizier who's done a very good job for the ruler — the ruler would present them with a special robe which would be placed over their shoulders.