During the etching process five keys are submerged in an etching solution. From time to time one of the objects is removed from the solution, until finally a small unrecognisable shape was left over.
During the galvanisation process, metal atoms from a copper sulphate solution are deposited onto the objects by means of electrolysis. Just like during the etching process, four keys have been subject to the chemical process for an increasing period of time.
Driessens & Verstappen, ‘Morphoteque #13’ (2003)