Pen Review: Uni-ball Signo UM-151 Gel Pen – 0.38 mm – Black

In keeping with the theme from last week, here is another liquid ink pen with a ballpoint. Specifically, it is the Uni-ball Signo UM-151 Gel Pen with a 0.38mm tip. The Signo is the type of Uni-ball ink and nib unit, which you may see at your favorite office supply store, however their line width is usually stopping around 0.7mm. Thus, I went online and found a thinner line width of 0.38mm.


First Impressions: The Signo UM-151 looks like many generic snap cap pens. Other than the writing on the clip, I would think it’s just some ballpoint that you could get at Wal-Mart of the Dollar Store to be honest. This is not a negative, I just think it looks relatively plain. Plain can be good, especially if you are tired of people borrowing your pens because they “look cool” or you don’t want to use a more upscale looking pen because of where you will be using it.

Design/Features: The pen has a clear body and cap. The clip is black and has the branding on it. There is a rubber grip for the section that is black that does like to collect lint, so it was grippy in the beginning but loses it as the lint cakes up on it. There is a chrome colored nib holding the Signo refill in the body. I do like that you can see your ink level since the body is clear and that you can just put in more ink refills rather than buying another pen. As I said earlier though, it looks like many generic ballpoint pens, which can be a good thing. This clip is a plastic clip that is pretty weak, so it does not hold your pen in place where you clip it.

Feel in the Hand: The pen is light and I really need to post the cap to get the balance right. Like I said above, the section was grippy in the beginning but as the lint collected, it loses its grip. Also the grip loosens up over about a week. The diameter is about average for a rollerball style pen. The section does not taper at all.

Writing: I like the Signo ink because it is a saturated black ink that is suppose to be theft proof according to Uni-ball. The pen does not need much if any pressure to write, which is good for being a pretty light pen. I had no issue with hard starts or skips. On every paper I used it leaves a very thin line, which is what I ‘m looking for in a 0.38 mm pen. But, just a disclaimer, it is a liquid gel ink, so it won’t write well on coated paper.


Use in clinic/hospital: I had no issue with hard starts or skips. It writes well, and leaves a thin line even on computer/copy paper. The cap is very small, so I had a hard time keeping track of it when running around the hospital. I had no issue with ink running out like I do with some liquid ink pens. I used the pen for 2 straight weeks and still had about half of the refill left. Also, no one asked to try my pen because it looked unique, which was nice because it decreases the chance of it walking away.

Price: You can find a package of 10 on Amazon for $15.90 or Jet Pens has them for sale as a single pen for $2.50. The price is not bad, especially for the package of 10 on Amazon.

Overall, this is a great pen. The ink keeps the thin line even on bad paper, the ink is suppose to be theft proof, the ink lasts a long time, it looks just like any generic pen, and it is not that expensive. I like this pen in my everyday carry on the wards or in clinic because it’s reliable, inexpensive, and the ink holds its line. The issue I have with it is that the diameter is still a little small for longer writing sessions, so for my lengthy writing this is not my choice.