Uni-ball Signo UMN-155 Retractable Gel Pen

Smooth, Scratch-Free Precision for Everyday Writing

The Uni-ball Signo UMN-155 (Signo RT1) redefines the gel pen writing experience with its innovative edge-less tip design. Engineered to eliminate paper friction, the rounded tip collar glides seamlessly across notebook pages and exam sheets without catching or scratching fibers, even at steep writing angles. Packed with Uni's proprietary archival pigment gel ink, each stroke delivers deep, rich lines that dry rapidly and resist fading, water, and bleed-through.

Designed for students, planners, and professionals alike, the streamlined barrel incorporates an ergonomic rubber grip that extends smoothly to the tip, providing fatigue-free control during marathon study sessions and fast-paced lectures.

Key Features

• Edge-Less Tip Geometry: Specially rounded tip housing reduces friction against paper surfaces for exceptionally low writing resistance.
• Archival Super Ink: Pigment-based formula binds strongly with paper fibers, offering water resistance, lightfast permanence, and fraud prevention.
• Quick-Drying & Smear-Resistant: Formulated to minimize smudges, making it an ideal tool for left-handed writers, bullet journaling, and timed exams.
• Integrated Ergonomic Grip: Continuous rubber contour provides a firm, comfortable hold without ridge pressure points.
• Convenient Retractable Design: Sturdy push-button click mechanism ensures quick one-handed deployment and prevents accidental pocket leaks.

Specifications

• Brand: Uni-ball (Mitsubishi Pencil)
• Model: UMN-155 (Signo RT1)
• Product Type: Retractable Gel Ink Pen
• Tip Sizes: 0.38 mm / 0.5 mm
• Ink Chemistry: Water-based pigment gel ink
• Barrel Material: Polycarbonate with molded rubber grip
• Compatible Refills: Uni UMR-85N (0.5 mm) / UMR-83E (0.38 mm)
• Country of Origin: Japan

Frequently Asked Questions

Does the ink smear when used with highlighters?
The Uni-ball Signo UMN-155 uses specialized pigment ink that cures rapidly into paper fibers. Once fully dry, it provides superior water and smudge resistance compared to standard dye-based gel inks, making it highly compatible with fluorescent and pastel highlighters.

Can I replace the ink cartridge once it runs out?
Yes, the UMN-155 is fully refillable. It accepts authentic Uni UMR-85N (0.5 mm) and UMR-83E (0.38 mm) gel ink refills, allowing you to swap colors or line widths while keeping the durable pen body.

Is this pen suitable for left-handed writers?
Yes. The low-viscosity pigment ink sets quickly on standard paper, significantly reducing hand smudging for left-handed note-takers and journaling enthusiasts.

How are orders and customer service inquiries supported?
For any order inquiries after purchase, you can contact our dedicated support team at szjyf@outlook.com. Full refunds are available at any time prior to order shipment confirmation.