Creating sculpture with molten glass is far more difficult than one would imagine. Skulls and other similar subject matter have bilateral symmetry this creates a unique challenge. This is because it is essential that the pipe or punty the gaffer is using be constantly turned on center to match the heat level in the glass to prevent torqueing and/or distortions. At some point in the making of a piece, the glass blower will have to stop, super-heat an area and manipulate the material. The timing of such actions is crucial not only for the area you are working on but likewise to prevent the undoing of the completed parts of the sculpture.