Kuretake's Dual Tip Black Calligraphy Marker : Our best selling in store the ZIG Calligraphy a double tip marker (2 widths): 2 and 5 mm, archival quality water-based pigment ink (acid-free), xylene-free so odorless. The colors are indelible and lightfast. Intense black ink that does not smudge. In addition, the special fiber of its tip is more rigid than that of the Pilot letterins pen. Once again Kuretake surpasses its competitors with this felt created by this firm which now has a long history behind it. Ink manufacturer since the 11th century !