There are many different casting techniques used to obtain a 3-D image of a foot. There are 3 main methods: plaster slipper, foam box and computer generated. Plaster slipper casting involves applying plaster directly to the foot and captures the contours and shape of your foot in a cast. Foam box involves pushing your foot into a foam box using a semi-weight bearing technique. Each casting method has advantages and disadvantages but a foot care specialist will choose the best option for your condition that gives a good foot impression.