Gubbio is recognized as a ceramics producer and, each of the shops along the routes in the old city, have a type of ceramic/pottery for sale. I' took some photos which show a diversity of styles, shapes, colors and designs that were openly visible. Some are very pretty, some are funny and others are a bit eccentric, but you be the judge.
Of all the cities so far visited, Gubbio is truly geared for the tourists with shops up and down the main streets in the old city, but all shops have tastefully avoided the overuse of tourist trinkets in the open. Ah, there are some, but what we found interesting is that there are modern boutiques built into medieval buildings.
Linda may be right, this isn't a topic of great historic significance. These small ceramic tiles are amusingly funny as each depicts a profession. I'm sure you can make out most of them without an interpretation. Good luck.