Winsor & Newton& 39;s range of calligraphy inks have 18 brilliant and lightfast colours. Brilliant Colours: The inks have been formulated with carefully chosen pigments to ensure maximum colour brilliance. Single pigments have been used where possible to enable clean colour mixes. Versatility for Pen or Brush: 14 colours (blue capped bottles) are suitable for dip pens fountain pens technical pens and airbrushes. These colours are transparent thinner in formulation fully intermixable and have a satin finish. Four colours (red capped bottles) are thicker opaque and should be used with a dip pen or brush; this also applies to any mixtures using these colours. The black and white inks have a matt finish. Permanence: Winsor & Newton Calligraphy Inks have a permanence rating of AA or A but are not waterproof. Flow: The Inks are non-clogging and have good flow characteristics when used in fountain or dip pens. We recommend that you test the inks with your chosen pen to ensure optimum performance. 30ml pots.