18 Lightfast colours with carefully chosen pigments to ensure colour brilliance.The 14 blue-capped bottles contain thinner more transparent inks with a satin finish. Suitable for dip-pens fountain pens technical pens and airbrushes. The four red-capped bottles are opaque and should be used with a dip-pen or brush.Winsor & Newton Calligraphy Inks have a permanence rating of AA or A but are not waterproof.