A method of manufacturing a three dimensional bio-model from medical image data is described. The method comprises: identifying a skin layer in the medical image data; determining a thickness of the skin layer; generating three dimensional model data from the medical image data, the three dimensional model data comprising an indication of a synthetic skin layer, the synthetic skin layer comprising a surface layer and a backing layer, wherein a combined thickness of the surface layer and the backing layer is determined from the thickness of the skin layer; and three dimensional printing the three dimensional model data to provide a three dimensional bio-model.