The object — the International Prototype Kilogram (or, as it's familiarly known, Le Grand K)-- is
held in France, with «
exact»
copies held at various crucial spots around the world, one of which is Canada's National Research Council.
Copyright seems to
hold some water here: if I write a letter, I have copyright in the form of words used, which would enable me, in theory at least, to stop unauthorized
copying; but we all know how powerful the laconic © assertion is nowadays, and, besides, it's usually the information and not the
exact language that the sender is worried about.