FUNORI: OVERVIEW OF A 300-YEAR-OLD CONSOLIDANT
JOSEPH R. SWIDER, & MARTHA SMITH
Over the last century conservation has seen an abundance of synthetic consolidants for adhering flaking paint and mending small fractures. The seaweed product funori, first used more than 300 years ago, is still produced today and can rival many other traditional and synthetic consolidants for its ease of use in a nontoxic form. Although funori has been employed for many years, references to its use and study are scarce. This article surveys the conservation and scientific literature on the use and chemical properties of funori. Preparation guidelines are provided for those who use funori or desire to experiment with it in their laboratories.
Funori is extracted from any of three species of red seaweed found mostly on the coasts of Japan: Gloiopeltis tenax (mafunori), Gloiopeltis complanata (hana-funori), or Gloiopeltis furcata (fukuro-funori), collectively referred to as the funorans. It is first recorded in Japan in 1673 as a size for textiles and papers and even as a cement for tiles and building materials (Chapman 1980). The seaweed is cultivated on rocks in Japan and is produced year-round. Processing funori is minimal: it is washed and soaked to remove debris and salts (fig. 1). Many modern processes use a bleaching agent such as potassium hydroxide or sodium peroxide after soaking, lightening the color of the seaweed to an orange-yellow. The fibers are shaped into mats, traditionally placed in the sun for further bleaching, and the dry mats are cut and rolled.