Three thousand spectacle frames are kept in one building. Sabae has been making eyewear for a hundred years and more, and the factories that make frames, the shops that sell them directly and the exhibition spaces are all inside the same small city. At the Megane Kaikan, frames from around fifty makers in the prefecture are displayed three thousand at a time, with a museum, a shop and a café sharing the premises. There is also a workshop where visitors cut and assemble a frame themselves, which is the quickest way to understand how a flat sheet of metal turns into something that sits on a face.

Shin-Takefu on the Hokuriku Shinkansen is close by, and job listings for eyewear and textiles appear all year round, so being a producing district shows up here in the plainest possible form: in what work is available. Having somewhere that all fifty makers will put their frames means something as well. These are competitors, and they have agreed to be shelved together, which is an arrangement more common in producing districts than outsiders assume.

Spectacles are worn on the face, so a difference of a few millimetres changes how they feel after four hours. Closing that gap is skilled work, and it is divided finely: there are factories here that do nothing but hinges, others that do nothing but the temple tips or the surface finishing. Seen that way, the wall of three thousand frames is not really a product range. It is an inventory of what that division of labour can do when it is all assembled in one place, which is more or less the definition of a producing district.