This White Garden Paintmarker Pen Can Be Used For Marking Almost All Surfaces, Ideal For Dark, Smooth, Transparent Surfaces Such As Glass, Metal Or Plastic As Well As Porous Surfaces Such As Terracotta And Wood. the Pen Uses Permanent, Waterproof, Low Odour, Lightfast, Smidgeproof, Quick-drying Pigment Ink For Easy Labelling On Lots Of Surfaces. The Valve Controlled Ink Flow Ensures Smooth Writing And The 2-4mm Nib Allows For Accurate Marking.ideal For Dark And Smooth Surfacesuses Permanent And Waterproof White Inklow Odour, Lightfast Quick Drying Inkcan Be Used On Porous Surfaces Such As Wood Terracottavalve Controlled Ink Flownib - 2-4mm