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Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue

by Uni

Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - UNI UMN103.33
  • Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - UNI UMN103.33
  • Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - UNI UMN103.33
  • Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - UNI UMN103.33
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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.


Frequently Bought Together
Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - UNI UMN103.33+Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Black - UNI UMN103.24
Total Price: $3.30
This item: Uni-ball Signo RT UM-138 Gel Ink Pen - 0.38 mm - Blue - $1.65

More To Explore

Pen Sets

Model NumberUNI UMN103.33
Shipping Weight0.35 oz
Body Color Blue
Body Material Plastic
Cartridge-Compatible Yes
Clip Material Plastic
Clippable Yes
Color Set No
Diameter - Grip 9.6 mm
Diameter - Max 10.6 mm
Grip Color Blue
Grip Material Rubber
Ink Characteristics Waterproof
Length - Extended 13.8 cm
Length - Retracted 13.9 cm
Mechanism Retractable
Pre-Installed Ink Color Blue
Tip Length 4.4 mm
Tip Material Metal
Tip Size 0.38 mm
Tip Type Conical

  I'm relatively new to..., February 20, 2013
By aus... - See all my reviews
I'm relatively new to the world of micro pens. The other micro pens I have are the mach IIs which are liquid ink and 0.4, the mach III (not on jetpens) which is 0.38 liquid ink, and the stylefit 0.38 gel. I will say that I am impressed with this pen. It does not skip and is pretty smooth, not to mention it's cheaper than the stylefit and has a larger ink refill. The ink refill isn't as big as it looks because the plastic walls of the refill are thick, but I'm pretty sure there's more ink than in a stylefit single refill. If you want an all purpose thin pen, I'd say based off my first impressions of writing that this is the pen for you. I haven't had this for a long time, but I am optimistic that it will turn out to be a great everyday usage pen.
  This pen has the best..., January 25, 2012
By ryo... - See all my reviews
This pen has the best "bright" blue color !

It's ink is not too dark, not too soft. Sarasa blue is too dark & Signo Light Blue is too pale for my eyes. This Uni-ball Signo RT Blue has the most beautiful blue color. I'm only using Signo RT Blue Black & this Blue for everyday use, for journaling, note taking, and drawing. Signo RT is the best pen... : )

  These are my everyday,..., December 2, 2009
By jmartini - See all my reviews
These are my everyday, go-to pens. I ordered a box of them six months ago and have been using them in a primary role ever since. I use them primarily at work, where I'll take notes, sketch designs and diagrams, markup drawings, and make notes in small notebooks.

The gel ink flows smoothly and looks great in blue. This is the same as the rest of Uniball's Signo line, although it tends to smear less while drying due to the smaller line. I like the shape and texture of the grip and the minimalist style of the pen. It writes very well, and is extremely precise. Sometimes it can skip, but generally only when writing large and quickly. Since most of my writing is smaller and precise, this pen fits perfectly.

  Smoothness: okay Precision:..., November 8, 2009
By khb... - See all my reviews
Smoothness: okay
Precision: okay
Weight: light
grip feeling: okay
cushion: solid

Overall: Okay. I personally prefer Pilot G-Knock Retractable Gel Ink Pen - 0.38 mm
for better grip and better nonslip feature of the cushion.
  Feels great on paper...., May 11, 2009
By breaker021 - See all my reviews
Feels great on paper. A little scratchy but perfect for jotting down very quick + short notes. I think it would make taking long notes really really slow so i would stick to the .5mm model which I love. either the UM-100 or the UM-151.