Water-based liquid chalk. Perfect for writing on magnetic glass boards, smooth glass and most sealed surfaces. Opaque coverage; the chisel tip enables different line widths (calligraphy-like effect); luminous, decorative lettering on all coloured boards and designs; makes a striking impression even when viewed from a distance; perfectly legible; dry or damp erase. Cannot be erased from porous, unsealed surfaces such as chalkboards, chalkboard paint or chalkboard foil. Before use, shake the pen and pump the nib on the writing surface several times until it fills with ink.