What happens when the fundamental rule of trade, according to which the one-time purchase of a product is sufficient to secure ownership, is cancelled in an artistic and playful way? “Natron” shows one and the same everyday product being bought a hundred times, a single packet of Kaiser-Natron washing powder, as can be found almost everywhere. It also explains stories around the action, from conversations with store detectives, baffled chemists and the creation of a specifically mercantile identity.