Where Al-Idrisi's map would have been engraved by hand, Factum Foundation's re-creation uses CNC milling machines to engrave the contours of cities and coastlines onto the silver surface. Far from representing a de-skilling of the engraving process, Factum Foundation's use of these machines pushes them to limits usually thought impossible: where CNC routing is often regarded as an imprecise method of rematerialising data due to the 'noise' left by the head of the drill, Factum is able to create remarkable precise reproductions by reworking the same surface multiple times in finer and finer detail, in materials ranging from wood to resin to alabaster.
Factum's CNC milling experts were able to translate the vectorised world map (shown below) into commands to the milling machine. The map was engraved in eight parts, with each plate measuring 500x1000mm. The engraving of each took 48 hours, and was performed using a spring-loaded tool, which is able to cut without rotating and applies a similar pressure to the thin plate (0.3mm thick) to that made during the hand-engraving process. The plates were fixed to the work surface using a contact glue which allows a degree of movement, allowing them to deform in response to the pressure of the engraving tool.
Once routed, the plates were cut and fitted together with the help of a silversmith.
The finished map in Factum Arte's workshops © Oak Taylor Smith for Factum Foundation
The finished world-map © Oak Taylor Smith for Factum Foundation
Factum team: Francesco Cigognetti, Francisco Regalado Abascal, Javier Barreno, Silvia Álvarez López-Doriga, Eduardo López Rodriguez, and Carlos Alonso Salamanca.