This Tombow Dual Brush Pen Primary Set contains 6 of these versatile markers, particularly popular with graphic artists and watercolourists but great for just about any kind of drawing. Each has two tips: a fine one that’s perfect for details and a flexible brush. The brush is durable yet soft for creating fine, medium or broad strokes, and is also ideal for filling larger areas with colour. The ink inside the pens won’t bleed, and is odourless and acid-free. Since it’s water-based, you can blend the colours, just as you would with watercolour paint.  The Tombow Dual Brush Pen Primary Set contains black, yellow, green, blue, pink and red.