|Long before the forged/poured boules there were the "nailed" boule cloutee. This manufacturer says that they use "Racines Wood" a region in the center of France.|
In order to identify boules apart, the boule cloutee had patterns of numbers, letters, emblems and such of different types of metals. The shapes of the nails also differed, some used the square nailheads, others, overlapping round nailheads to create a "fish-scale" effect. I think they're quite beautiful looking.