Uni-ball Signo RT UM-138 Gel Pen - 0.38 mm - Black

Uni-ball Signo RT UM-138 Gel Pen - 0.38 mm - Black

In stock and ships within 1 business day.
4.6 (37 reviews)
DescriptionSpecificationsFrequently Asked Questions
Uni Signo RT gel ink pens contain water-based pigment gel ink and feature a retractable 0.38 mm gel ink roller ball pen, rubber grip, and a steel point for strength.

Super practical and affordable, the Signo RT pens have been a long time tried and true favorite of JetPals.

Customers Who Bought This Item Also Bought

Curated Collections

Articles & Guides

Customer Reviews

While the 0.38mm tip...
June 8, 2011
Verified Purchase
While the 0.38mm tip writes fine lines, I am rather disappointed in the ink reservoir. If you pay close attention, the inner diameter on the refill is much smaller than most normal refillable pens which explains why these pens have such a short lifespan. The inner diameter on this refill is 2mm (approximately 3/32”) whereas other pens, like the Zebra Sarasa or the Uni-ball Signo 0.5mm, have a much wider inner diameter. These pens have a 5mm (approximately 5/32”) inner diameter, resulting in 2.5 times more ink than the Signo 0.38mm RT. It’s a great price, especially for those who love super fine tips. Me? I’ll take the extra ink with a 0.5mm tip.
5 people found this helpful
To the guy who is complaining...
January 18, 2012
To the guy who is complaining about the reservoir size. It isn't that the .38 size has a smaller reservoir in particular, it's that the retractable signo's as a model have a smaller reservoir. Any size of signo DX models will have the same size reservoir. If you want .38 and still want a big reservoir go look at the .38 signo DXs. They also come in .28 and .5 btw. Anyways, the pen itself has been good to me as all the models of signo I've tried have been. Other than that sometimes not having to worry about a cap can be a good thing. Also, the grip is farther down the pen, which is better for me because I hold pens closer to the tip, which with the Signo DX model is pretty far up so I end up holding past the grip anyways.
4 people found this helpful
The greatest pen on this...
February 9, 2015
Verified Purchase
The greatest pen on this Website. Buy it immediately.

1 person found this helpful
I love these pens. They...
November 24, 2014
Verified Purchase
I love these pens. They are by far the best pens I have ever written with. I have ordered 6 refills and I bought the pack of assorted colors because they are great. I use the different colors for taking notes at school. I like how pointy and fine they are. I have gotten other brands of 0.38 and 0.4, but this is by far my favorite.
1 person found this helpful
I ordered this pen along...
November 12, 2015
Verified Purchase
I ordered this pen along with 9 others in an attempt to find a fine enough point to suit my writing style and desires. I tested this pen immediately after trying the Uni-ball Signo UM-151 Gel Pen - 0.38 mm, which is the non retractable version of the same pen, or so I thought. Perhaps it was just the pens I got, but this pen wrote noticibly thinner than the UM-151, and goes above it in the list of likely candidates to become 'my pen'. I enjoyed using this pen, and continue to carry it at work while conducting my other trials.