Computed axial lithography (CAL) is a method of 3D printing that is based on computerised tomography scans, whereby it creates objects from photo-curable resin. [1] [2] [3] [4] The process was developed by a collaboration between the University of California, Berkeley and the Lawrence Livermore National Laboratory. [5] CAL is distinguished from, for example, the fused deposition modelling and stereolithography 3D-printing models, in that it does not build models by means of depositing consecutive layers of material; instead, it projects a set of 2D images of the intended 3D product, onto a cylinder of resin, while both the images and the resin spin at the same rate. [1] [5] CAL is also notable for its ability to build an object often in mere seconds—much more quickly than other methods using resins; moreover, it can simultaneously make multiple objects, one embedded inside another, within the same active process.