The Natura Dualis collection by Van Diemans brings together moments in nature where contrast and harmony coexist. Each ink is formulated not only for visual beauty, but for movement dual and multi-shading behaviour, halos, colour splits, and rivering that reflect the changing character of the natural world. Like dawn breaking over land, or water surging beneath stillness, these inks never show just one face.

Underflow is inspired by hidden strength that quiet, unseen current just below the surface. Where Sea Spray glides and Riverbank roots, Underflow moves slow, deliberate, and steady. It represents the pull of the tide, the motion you feel before you see it. This ink doesnt shout; it draws you in.

On paper, it flows in a cool sea-glass blue, fading into mauve-violet underlayers and rimmed with teal-toned halos where it pools. Its duality is striking equal parts aquatic and atmospheric. In finer nibs, it appears clean and modern. With broader nibs and shading paper, it unfurls into a beautifully separated spectrum of oceanic tones, with a distinct sense of motion even in still lines.

Underflow is contemplative, modern, and deceptively complex for those drawn to depth rather than drama.