The core shell for the prototype was to be made out of glasfiber, but to get an exact shell we needed to make a mould, a shape of the chair on to which we could add the gelcoat and glassfiber. Such a shape is milled out of a fine type of styrofoam, sandpapered and surface-treated. The milling is done by a computer operated saw/mill/ CNC operated directly from the three-dimensional CAD design.

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The size of the Ballerina Sweetspot meant that that there were few of these saws that could actually do the job with the level of precision and refinement needed. We chose a company called Macromould (www.macromould.se), usually involved in developing and cutting out moulds for boathulls with their 5 axis CNC mills.

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Two weeks after they received the file, at the end of March 2009, the styrofoam mould was shipped to Modellservice in Norrtälje approx. 70 kms outside. Judging only from the mould, it was an impressive design.