I think I've mentioned the Book of Old-Time TRADES AND TOOLS before.
Looking closely at some of the engravings I noticed that a lot of workers are wearing folded paper hats.
I thought this was called a Joiner's Hat made from a sheet of newspaper but they appear in lots of trades such as Bricklayers, Needlemakers, Tinners, Printers, Plumbers and Brass Founders for example.
Here's how to make one courtesy of Raphael Salaman's Dictionary of Woodworking tools...
if you can find a broadsheet any more.