In stock and ships within 1 business day.
4.6 (5 reviews)
Uni-ball Signo UM-151 gel ink pens, also known as Signo DX, are known for their smooth writing and exceptional ink quality. And, to everyone's delight, there is a sea of colors and tip sizes to choose from. Find the perfect pen for any task, whether it's writing meticulous notes, marking your calendar, or decorating your scrapbook with colorful captions.

Everything about this pen, from its solid construction to its carefully-formulated ink, ensures a wonderful writing experience. The sturdy tip does not bend or break, even with heavy-handed use. The pigment-based ink flows smoothly and is waterproof, fade-resistant, and feather-resistant. Much of that is due to special viscous properties of the ink. The ink is viscous while in the barrel, but as it passes through the pen tip during writing, the viscosity drops. This results in smooth ink flow. Immediately after it hits the paper, the ink returns to its viscous state, which prevents feathering. You are left with beautiful clean lines that you can enjoy for a long time!

This is the Blue pen. The close-up tip photo features the Black pen.

Model NumberUNI UM15105.33
Weight0.4 ounces
Body Color Clear
Body Material Plastic
Clip Material Plastic
Clippable Yes
Color Set No
Diameter - Grip 10.2 mm
Diameter - Max 10.2 mm
Grip Color Blue
Grip Material Rubber
Ink Refillable Yes
Length - Capped 13.8 cm
Length - Posted 15.2 cm
Length - Uncapped 13.1 cm
Mechanism Capped
Pre-Installed Ink Color Blue
Tip Length 4.3 mm
Tip Material Metal
Tip Size 0.5 mm
Tip Type Conical

Frequently Bought Together

Uni-ball Signo UM-151 Gel Ink Pen - 0.5 mm - Blue - UNI UM15105.33
Uni-ball Signo UM-151 Gel Ink Pen - 0.5 mm - Black - UNI UM15105.24
Uni-ball Signo UM-151 Gel Ink Pen - 0.5 mm - Blue Black - UNI UM15105.64
Total Price: $7.50
This item: Uni-ball Signo UM-151 Gel Ink Pen - 0.5 mm - Blue - $2.50

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Customer Reviews

As much as I love retractable...
January 10, 2015
Verified Purchase
As much as I love retractable clicker pens so I don't have to worry about losing the cap, the Signo UM-151 in 0.5 is the smoothest, most reliable, and most visually pleasing ink and body amongst all the pens I've used (Zebra Sarasa 0.3, Hi Tec C 0.4, Signo 207 0.5 & 0.38, Jetstream 0.7 & 0.5, Uni Style Fit 0.38).
This blue is bright (unlike Sarasa's blue which is oddly closer to navy or blue-black) without looking silly. I look forward to using this pen for many years to come and just continuing with refills.
I like the larger size...
December 8, 2009
Verified Purchase
I like the larger size barrel compared to the Hi-Tec-C and Slicci pens. The rubber grip is nice, and it runs a clean line. I found that the ink is waterproof as advertised.
Excellent pen for note...
May 11, 2009
Verified Purchase
Excellent pen for note taking! nice, controlled and THIN lines, good size barrel, does not scratch onto paper, etc. This is my favorite pen for note taking for long periods!
I've been using this...
March 23, 2009
Verified Purchase
I've been using this pen for the past few days after a recent shipment, and I have to say it writes like a dream.

I personally haven't had an smudging issues. It's everything I've been looking for: a decent grip, .5 mm line and smooth ink flow.

I just wish they sold them in the US.
Although the Signo DX...
October 26, 2008
Although the Signo DX 0.5mm pen writes more smoothly than the 0.38mm version, the 0.5mm Signo DX has certain issues with giving out too much ink when writing. Smudging is a real possibility when writing with this pen.