The Uni range of Posca Markers all use a high-quality water-based ink which is waterproof & lightfast meaning long lasting results even when exposed to light. The Markers are highly adaptable as they can be used on a variety of surfaces ranging from glass to PVC to wood & cork, as well as giving permanent results on card & paper without the risk of any seepage. The Posca range come in an array of tips suitable for any project including pin, chisel, bullet & brush tips with most of them being replacable & and washable with warm water.