Literature: “Axel Salto - Stentøjsmesteren”, CLAY - Keramikmuseum Danmark, the model ill. p. 38–39.

Literature: Axel Salto: “Den Spirende Stil”, the model ill. p. 48.

Literature: Leif Lautrup-Larsen: “Stentøj”, the model ill. pp. 362–363.

The Solfatara glaze is best used on objects requiring modelling or relief patterns. Therefore, the Solfatara glaze was ideal for Salto's design, and he himself believed that the Solfatara and Sung glaze contributed to the most fascinating and touching achievements in his stoneware production. The glaze is a result of the collaboration between H.A.L. Madslund and Nils Thorsson in 1936. Salto was – like other ceramic artists at Royal Copenhagen – a true believer of the Solfatara glaze's distinct acid green colour. With Salto's death in 1961, the Solfatara glaze was phased out, since he at this point was the only one left at the factory still using this glaze type.