The set designer will frequently add elements to the scenery to enhance it. Perfectly integrated, elements that are light as a feather can become monumental in appearance.
Polystyrene and polyurethane foam which are light and easy to sculpt are mainly used. Polystyrene is easy to cut and shape. It is cut using a hot wire.
Plaster is also used to create architectural elements, columns, mouldings, and floral ornaments.
The main tools of the sculptors are bandsaws, chainsaws, knives, brushes, rasps, etc. Plaster and mouldings
either a photo projected onto polystyrene, in the desired size, like for the giant raven in Der Rosenkavalier
or miniature sculpted clay models, like for the statues for the scenery for Henry VIII
One of the challenges that Christophe Coppens set the Workshops for his production of Norma (2021) was to suspend a car made of (fake!) concrete above the stage!
The sculptors made moulds and reproduced a real car using silicone, resin, and fibreglass, which helped to greatly reduce the weight of the car.