This marker has a large 1-1/4" wide tip. It makes a 30mm mark. High Opacity, Water-based pigmented ink. Marks on most surfaces- including glass, metal, wood and plastic. Great for advertisements on glass. Marks stay on glass until you wash them off with glass cleaner. Also suitable for marking paper, plastic, mirrors, wood and stone. Great on posterboard and chalkboards. Safe / Non-Toxic.