Black Fine-Tip Dixon Vis-Aid Waterbased Overhead Projection Markers. Rated #1 of the 3 brands that Filmtools carries. Better than Vis-a-Vis and Lumocolor. Wet Erase (Erases with a damp cloth.) Waterbased Ink, Odorless. Superstore prices.
Made by the Pencil People: Dixon Ticonderoga.