Silver Uni-ball PC-1MR Posca markers are poster coloured markers that use water-based ink. These pens are great for drawing posters, sketching and flipcharts. The pens are suitable for paper and can be applied on metals, plastic, vinyl and glass. The sharpest marker in the Posca range, the PC-1MR has an ultra-fine pin tip which can be used for fine detail in any artistic situation.