Several months ago, my friend sent me this lovely little oddity. It is the Pentel B-100 Pen. Overall, the pen looks like your standard budget disposable pen. But its not what it appears. The body of all the pens are green (Pantone Color of the Year Emerald, I might add) with the tips indicating the color. Mine is a clear red ink but the pen is also available in black from Kiosk. It wasn’t until I started writing with it that I realized it was quite unusual.
The pen has some line-width variation I would not have expected in a rollerball or fiber-tipped pen. It writes almost like a stub nib fountain pen or a small calligraphy nib. Looking closely at the point I couldn’t quite figure out exactly what it is. My best guess is that it is a rollerball but the translucent plastic casing around the ball is slightly flexible allowing the line to flow a bit differently than a rigid plastic rollerball.
It is not water-proof but water-resistant enough to be used on envelopes or folders. On my testing paper (the Miquelrius grid notebook), I got a little bit of show through on the back side of the page but it was nominal. On good quality paper, this pen could be used on both the front and reverse of the paper without any readability issues.
Overall, I quite like this pen. It wrote smoothly, offered line variation not often found in a disposable pen and the body is a lovely green, concealing the fun of bright, red ink inside.
Pens are sold individually for $4 each from Kiosk with a wonderful little card with a story about the pen.