3D Printer Babbling
When you set up your 'slicer' - the software that turns a model into a set of printer instructions - you can specify the rate of travel for the extruder at various tasks. For perimeters - the 'sides' of a print - you usually want to print the outermost wall slower than the inner walls, which gives it a smoother texture.
Apparently, though, you *can* get that backwards and it'll still work for big enough pieces. >.<