Double "Ravenna" decoration. Signed ORREFORS Ravenna Nr 4621 Sven Palmqvist. Orrefors archive - sold to the department store NK in Stockholm 28 September 1970 for 375 kronor ( € 37)
Ravenna technique was developed by Sven Palmqvist for Orrefors in 1948 after a trip to Italy, fascinated by the byzantine mosaics, windows and patterns that he saw in Ravenna. A colored glass layer is put on top of a clear one and these are then flattened. The motive is created by sandblasting away the colored layer of glass to expose the clear glass. Powdered colored glass or pigments are then scattered into the applied design before being encased with clear glass. Small air bubbles are trapped in the design. The glass is then reheated and formed to their final shape. Sven Palmqvist was the only person to work in the Ravenna technique at Orrefors.