Derwent Academy Set of 8 Twin-tip Markers Derwent Academy's twin-tip markers are water-based with a brush and a fine tip, giving you the flexibility to do a stylish and detailed job or to apply a lot of colour to the page quickly. The tip of the brush creates thick, fine lines with a brushstroke. The thin tip has a wide tip for maximum control. Explore a wide range of techniques such as dotting, shading, layering, and mixing. Apply the light colours on the first page to avoid transferring dark ink to the tips of other markers. Just apply enough pressure to prevent damage to the tip of your marker.