Hi David, thank you so much for your lovely comment! My choice of ballpoint pen as my current art medium is directly influenced by a Japanese artist Shohei Otomo.
At first I was wondering if he used some ink applications, not only a pen, to produce that really smooth grey gradations of human skins. But as the video introduced in the above article shows, he doesn’t…he does all the grey parts using incredibly diligent hatching only. This is possible because he uses a ballpoint pen. In particular, with the brand he uses, it’s zebra rubber 80, an 80 JPY ballpoint pen you used to see quite often at bank counters in Japan, you can readily draw grey lines, not black ones. Matt mentions this particular characteristics of ballpoint pen in one of his critiques of my drawing, at around 10:39. I was lucky that I bumped into Shohei’s works while I was thinking about which gadgets I should buy for my new attempt at pen drawings(before that, I used soft pastels for my drawings). I checked some fountain pens of course, and some popular fine liner pens were also in my potential shopping list, but I ended up buying only Shohei’s ballpoint pens because I did not see the necessity of getting anything else once I saw Shohei being able to draw anything like that with a ballpoint pen. I understood that it would be a question of how to utilize the gadget of your choice to its full potential.
Hope I have answered your questions sufficiently! 
