Figure 1. Mode of the grey-levels histogram of the wax layer during progressive deformation. The mode is a measure of the quantity of melt visible on the edge of the model. Pure melt and melt-depleted wax have a darkness of 100% and 25%, respectively. The darker is the layer, the higher is the melt fraction. The running average is computed on 3 consecutive values. The graph shows a net decrease during the run but with periodic variations that correspond to successive pulses of melt extraction.