Chalk markers and paint markers are two of the best types of writing utensils to use for writing on glass. These pens also work well on smooth, hard surfaces, such as metal or plastic.
If the marks that need to be written on a glass surface must also be erasable at a later time, use a grease pencil or a dry-erase marker. Grease pencils, sometimes known as glass markers or china markers, are used in laboratories to mark glassware as well as for marking glass to be installed in a construction project. Grease pencil marks are removed from glass with window cleaning fluid or a mild soap while dry-erase markers wipe off of the glass surface with a cloth.