I'm making my aglets out of commercially available brass, usually 0.2mm because that seems to be the middle of the range for the extant aglets that I've seen records for (imagine I've put a link to Gerald's paper here...)

There's a metaphorical rabbit-hole I'm going to dive into one of these days looking at where the brass was made, and by whom, and see if that provides any insights into the overall economy that leads to aglets.