1.Product features: 0.45mm ultra-fine tips, using quick-drying, non-toxic, waterproof ink, stable and smooth writing, stable and clear lines. Suitable for painting, drawing & art supplies, note taking, planning, sketching, cartooning, madhubani painting, colouring books, comics. 2.Product Description: The micro-line pens set contains 12 pens with 12 kinds of unique colours, 13cm in length and 113g in weight. 3.Note: If the micro pens can not produce ink normally, it is because the tips of the colour fineliner pens have a layer of primary protective film, please put the nibs into the water and shake it for a few times, then it can be used normally.