It's magic! The Cutter 08 BMI from Grog is filled with Black Magic Ink, an invisible mixture that reacts with UV rays up to its complete dulling, becoming an intense dark brown color. The Cutter 08 BMI marker is made of a rigid plastic barrel, equipped with a robust 8mm Quickflow chisel tip and an anti-drip closure cap.
With Cutter with 08 BMI you can experiment calligraphy works with different color depths, because Black Magic Ink will darken as much as how much light it will absorb, or writing outdoor without being seen by anyone, because the Black Magic Ink will activate only after absorbing a decent amount of light.
Refillable, exchangable 8mm Grog Quickflow Tip.