Robert Oster bottle ink, Sinner's Poison, 50ml

Robert Oster Signature Ink – Sinner's Poison

Sinner's Poison is a colour that draws you in with its dark allure and striking presence. Deep, cool and mysterious, it moves between shadowed greens and inky teal tones, revealing a quiet intensity as it dries. There is a controlled drama to this ink, a sense of something potent beneath the surface, making it an unforgettable shade on the page.

Crafted in South Australia, Sinner's Poison offers the smooth flow, expressive shading and reliable behaviour that define Robert Oster’s work. Whether used for journaling, creative writing or artistic expression, it brings a bold yet refined character to every stroke.

A drink for your pen.

The Remarkable Robert Oster

Robert Oster is a South Australian colour creator whose inks reflect passion, artistry and a deep connection to the Australian landscape. His colours are known worldwide for their expressive shading, reliability and distinctive character.

Each bottle of Robert Oster Signature Ink is handmade in Australia and presented in a recyclable 50 ml PET bottle produced in Australia’s first carbon neutral plastics plant. These inks are non-toxic and environmentally considerate, created with care for both the writer and the world they write in.