Steel BlueBottled Ink by Diamine is non-toxic water-based fountain pen ink that can be used with any fountain pen and will not clog your pen. A secret ingredient has been added by Diamine – producingsmooth flowing, vibrant colors that glide across your paper surface. Available in over 200 variations, you are sure to find the perfect color for your writing needs! Volume:Ink Cartridges (18 ea)Short International Color Family:Blue