0.4 mm is the sweet spot and Pilot nails it with the Hi-Tec-C Gel Ink Pens. I
find that holding the pen tilted to any side gives great results, just as if you
were holding the pen straight up and writing. My only qualm with the pen is that
after the first initial uses, if you haven't used the pen in a few hours, when
you go to write again the amount of ink coming out isn't consistent for the
first few strokes but after that your smooth sailing again. I HIGHLY recommend
this pen for the avid writer!
This is a very nice, fine-tipped pen. Sometimes the pen skips and the ball at
the tip feels like it got stuck on something, so you just have to scribble to
get it working again. This doesn't happen often, but enough to warrant a
comment. Other than that, I highly recommend this pen.