I use a Schneider topball 845. It's very consistent, smooth, sharp and without smearing. It's 0.3 mm though, but a rollerball so it leaves a more saturated and

I use a Schneider topball 845. It's very consistent, smooth, sharp and without smearing. It's 0.3 mm though, but a rollerball so it leaves a more saturated and wider writing trail than a ballpoint pen.