Meanings of written in pen in English

They had written in pen, in pencil, in paint; their self-help slogans crisscrossed dirty walls.

Some were written in pen and ink, and some in pencil, but all were equally brown, worn, and unsavory in appearance.

The first sheet is executive mansion stationary and the words written on it are written in pen, with some pencilled in amendments at the bottom.

The manuscript's first page of the final chapter shows Chapter XXXI crossed out and XXVII written in pen, confirming that four chapters had been removed.