UNI-BALL POSCA PC-1MR BLACK PACK OF 12 PENS Uni-Ball POSCA PC-1Mr Pack of 12 - Black Writes on: Metal, Glass, Plastic, Stone, Fabric, Photographs etc. - Virtually Any Surface Reliable: no line variation, consistent results when rendering Original: combines the accuracy of a pen with the quality of paint. Pack of 12 pens