BiC Cristal 1.6 mm Colors 18838, Xtra Bold Point, Pack of 24 Pens, 8 Ink Colors. Cristal Ballpoint Pens feature a clear barrel so you can see the available ink supply and a roll-proof, hexagon-shaped barrel for comfortable controlled writing. Design includes a ventilated cap and brass medium point with tungsten carbide ball. Cap color matches ink color. Pen delivers long-lasting dependability and smooth writing and writes with consistent, sharp, effortless lines. Ballpoint pens are nonrefillable. Ink colors include: Blue, Green, Black, Purple, Lime, Pink, Aqua and Red.