If it is too thin, it is difficult to read, if it is thicker or thicker it can not write in the narrow entry field.
I liked it at work and I started using it for private use.
It is delicately fine and fine, I have patronized many years.
At the beginning of use, the ink got drunk. ... but after a short time the ink gets stuck or the ball part becomes hard and it gets faint. I like microfine and I have been using it all the time, but as performance I think now is one more thing.