FiDU, from German Freie Innendruck Umformung, is a method of creating objects on various scales, from two-dimensional (2.5) sheets of flat metal welded together using internal pressure. It is based on a free deformation process, known also as volumetric expansion. Moreover, production files required to define the 2.5D form are just a few kilobytes when allowing for a ‘controlled loss of control’. Trying to define the same final form for traditional production methods would require several gigabytes of data.