Funori is a polysaccharide extracted from the red alga Gloiopeltis furcata. This polysaccharide is generally known in conservation for its advantages as a product to consolidate matt paint. Because of variations in quality of the traditional Funori, the authors developed an extraction method and a purification procedure to obtain the pure polymer called JunFunori. The improved adhesive was tested in comparison with traditional aqueous consolidants such as gelatin, sturgeon glue, Klucel E (hydroxypropylcellulose) and Methocel MC (methylcellulose). The investigations showed that consolidation using JunFunori hardly changes the appearance of unbound pigment layer on canvas, in contrast to a consolidation using Klucel E. Accelerated ageing tests with a simultaneous influance of UV light and variations in humidity, in combination with mechanical tests and FTIR analysis demonstrated that JunFunori shows a good stability under this specific conditions. In liability tests JunFunori was as resistant to biological attack as the other consolidants tested. These results indicate that JunFunori demonstrates high potential as an alternative to traditional consolidants.

Contact, Partner & Publications

Contact @ Empa
Thomas Geiger


Institut für Denkmalpflege ETHZ
Schweiz. Landesmuseum, Atelier für Konservierung/Restaurierung von Gemälde & Skulpturen (Anita Reichlin, Geneviève Teoh-Sapkota, Françoise Michel)



  • Senn, M.; Devos, W; Fasnacht, W.; Geiger, T.; Michel, F.; Ritter, A.; Fortunato, G., An Odyssy Through Time at EMPA., Chimia 55 (2001) 931-937
  • Michel, F.; Geiger, T.; Reichlin, A.; Teoh-Sapkota, G., Funori, ein japanisches Festigungsmittel für matte Malerei., Zeitschrift für Kunsttechnologie und Konservierung 2 (2002) 257-276
  • Michel, F.; Geiger, T.; Reichlin, A.; Schleuniger, J.; Teoh-Sapkota, G., JunFunori - a natural polymer from red algae to consolidate matte paint, In: Proceedings, The International Institute For Conservation Of Historic And Artistic Works, 20th International Congress, September 13-17, 2004, Bilbao (Spain)
  • Geiger, T.; Michel, F., Studies on the polysaccharide JunFunori used to consolidate matt paint, Studies in Conservation 50 (3) (2005) 193-204
  • Geiger, T., Traditionelles Festigungsmittel rettet alte Meisterwerke, Applica, 20 (2007) 14


Status: completed