Vapor-glazing process touted as modern-day non-toxic replacement for salt-firing. Gives slightly less gloss and orange-peel. Instead of salt, soda ash (sodium carbonate) in water solution is sprayed into kiln at maturing temperature, and sodium vapour combines with silica in clay to form sodium-silicate glaze. Recent research indicates that effluent gases are highly corrosive, and no more benign (or destructive) than salt-firing fumes.