Milan 2014: Tomas Libertiny's design studio used multiple body casts to dictate the shape of this seat for Dutch brand Tchai International, shown in Milan last month.

Rotterdam-based Studio Libertiny shaped the vacuum-formed thermoplastic seat and back of the Tchair by using plaster casts of different people to create the optimum form for overall comfort.

"Several casts were made in plaster to give us as the information to work from," Libertiny told Dezeen. "These were gradually sanded down to fit as many types of body types as possible without loosing the desired comfort level. The final plaster model was 3D scanned and further revised in CAD software."

The thin plastic seat is curved to support the inner thighs and angled to optimise blood flow to the lower leg.

"For a couple years I contemplated the idea of a chair that has both soft and rigid parts in one material," said Libertiny. "Tchair is a raw translation of this ideal in an affordable industrial product."

Tchair is designed for both indoor and outdoor use, and has an inbuilt flexibility for additional comfort.

The studio used structural steel to create the four curved legs and two bars that support the back.

"[Steel] was chosen because we needed to maximise strength while minimising its weight and because of its good welding properties," Libertiny explained.

Produced by Tchai International, the chair was exhibited at Ventura Lambrate, Spazio Rossana Orlandi and Museo Baggati Valsecchi in Milan during the city's design week.

Photography is by Jacob van Rozelaar.