The Zebra calligraphy nibs were designed specifically for comic and manga drawing, but have quickly become a favourite among artists and calligraphers. 

The hard G nib is designed to be firmer than the regular G nib, making it easier to create thin, consistent lines. For example, at 250 grams of writing pressure this nib will create a 0.24 mm line while a regular G nib would create a 0.31 mm line. It is also more durable than a typical G nib, having been treated with a special boron coating. The hard G nib can write a thin, uniform line for about 40 meters - twice as long as a typical G nib.