An oil-based ink that writes smoothly and deeply with acro ink.
"Acro Ink" is about 1/5 of the ink viscosity compared to our oil based ink.
In addition, it is formulated with a lubricant to reduce the friction resistance of the ball at the nib, resulting in smooth rotation and a deeper brush stroke.
Of course, it has excellent water resistance that is unique to oil-based ink.

From the Manufacturer

Reduces strain on neck, shoulders, and arms.

Since its launch, the Dr. Grip series has established a new field of writing instruments to reduce fatigue.In cooperation with Professor Yoshida, the Tokai University University University University University University and Affairs Design Science, "Easy to move writing instruments" were achieved based on experimental data.

Weight Balance

It focuses on the first time writing instrument.By reducing both ends of the pen, the weight is concentrated on the center of gravity that acts as the rotational axis of a writing instrument, making it easy to move.By reducing the value of inertia moment of inertia *, you can control the pen with less force and relieve the burden on your hands.