Modifiche

The last series produced in celluloid, the [[Columbus 90]] was introduced approximately in [[1951]], and made both as [[piston filler]] or with a special [[button filler]] with the bottom back not removable, similar to the ''[[push-knob]]'' of [[Montblanc]]. The production of the '50s saw the abandonment of celluloid for the use of cheaper molded plastic, and the production of [[Columbus Anni '50|models]] with [[hooded nib]] and cheap plastic pens for the student market.

The last series produced in celluloid, the [[Columbus 90]], was introduced approximately in [[1951]], and was made both with a [[piston filler]] or with a special [[button filler]] with the back knob not removable, very similar to the [[Montblanc]] ''[[push-knob]]''. The production of the '50s saw the abandonment of celluloid for the use of cheaper molded plastic, and the production of [[hooded nib]] [[Columbus Anni '50|models]] and other cheap plastic pens for the student market.