Parts are made with FDM technology by fusing and extruding different thermoplastics over successive layers. The machine first lays out one or more contours, which are then filled with a grid alternating 90° on every second layer. It is worth noting that there will be so-called voids (small holes) where the grid turns towards the contours; the parts are therefore not watertight. There is a choice of many different thermoplastics, and this is also one of the strengths of this technology. A water-soluble support is used for most materials, so the support for complicated geometries can then be washed off. For parts made from Ultem, however, the support must be removed mechanically, which imposes some limitations on how complex parts can be when printed from this material. FDM technology delivers good dimensional accuracy, but slightly worse resolution than competing technologies. The layer thicknesses we use are 0.17 or 0.25 mm. Some materials can only be printed with 0.25 mm. The time required for manufacture using FDM technology differs from other technologies; the synergy effects from building many parts simultaneously are not as evident as with SLS technology.