Figure 4. Absolute differences between original surface and each impression medium for the rough surface (a), and the smooth surface (b), generated using the SSFA parameterisation method.

Points show the actual differences from the original surface, with zero indicating the same value for replica and original surface. Each quadrant has been given a specific colour (NE = Blue, SE = Green, SW = Red, NW = Orange). Lines connecting points horizontally show mean difference. Whiskers represent the range of the data.