− | The silver surface processing called ''tula'', better known in jewelery as ''[[niello]]'', is one of the variants used to made [[overlay]] decorations during in the early period of fountain pens. This process was typical of European production (and in particular has been used by [[Kaweco]]). | + | The silver processing called ''tula'', better known in jewelery as ''[[niello]]'', is one of the variants used to made [[overlay]] decorations during in the early period of fountain pens. This process was typical of European production (and in particular has been used by [[Kaweco]]). |