Write on almost any surface with this pack of 39, versatile and highly pigmented uni posca marker pens in an assortment of colours with medium, bullet fibre tips.this set of uni posca marker pens features a medium bullet tip which offers unlimited freedom of use, whether you are drawing lines or colouring in. They contain a water based ink which produces no odour.smooth surfaces such as glass, glazed ceramics, pvc and smooth metal means your design will need fixing with a spray of water based varnish, apart from glass which should be put in a 160 degree oven for 45 minutes beforehand.instructions on how to make permanent terracotta by baking at 220 degrees for 45 minutes, then spraying with clear varnish porcelain by baking at 160 degrees for 45 minutes, then spraying with clear varnish glass by baking in the oven at 160 degrees for 45 minutes then spraying with clear varnish textiles by ironing on reverse metal, plastic and wood by spraying with clear varnish. Medium 1.8 2.5mm line width. Pack of 39. Will write on almost any surface . Water based. Permanent on porous surfaces. Erasable on smooth surfaces. Bleed proof on paper and card. Approximate dimensions mm h 310 w 225 d 58