Japan’s Mitsubishi Uni-ball ONE series black gel pen has been recognized as the world’s blackest gel pen by Guinness World Records.

When it comes to the world’s blackest paint, there is no competing with Vanta Black, but pen gel is a whole other matter. Mitsubishi Pencil Co.Ltd. now holds the record for the blackest gel pen, thanks to an innovative type of pigment-containing particles that seal the paint inside. When writing on paper, it can reduce the penetration of the gel into paper fibers, making the color look more saturated than other gel pens.

You’re probably asking yourself ‘what use do I have for a blacker-than-average gel pen?’. Well, Mitsubishi Pencil Co.Ltd. reportedly teamed up with Ritsumeikan University to conduct a memory test using various black gel pens and learned that blacker characters were easier to remember.

“When we compared the memorization performance of handwritten characters with ballpoint pens of different shades, we found that characters written with Uni-ball One’s dark black gel had a higher correct answer rate and a higher recall rate than those written with general gel ink,” the Japanese company wrote in a press release.

The newly developed Uniball One gel pen changes the ratio of solid to liquid components in the gel, making it possible for the liquid component to quickly permeate the paper surface while leaving the solid coloring material on the paper surface. So even though the ink remains quick-drying, the solid components on the surface give the writing a more saturated look.