The Pentel Arts Tradio calligraphy pen features a firm, but resilient iridium nib that allows you to draw thick to thin lines depending on the angle of the pen. Ideal for calligraphy, lettering or any stylized drawing. Each pen comes with a Black ink cartridge inside and is refillable with any International standard ink cartridge. Available nib sizes are 1. 21mm, 1. 4mm and 1. 8mm.