Tombow Zoom L1 Review: A Transparent-Looking Pen with a Clever Gel Refill

Introduction

The Zoom brand, previously part of Tombow’s lineup, has been spun off as its own brand, and its launch brought three new pens to market at once. The Zoom L1 is one of those three, and it is the most intriguing of the bunch on paper: a capped water-based ballpoint pen priced at 4,400 yen including tax, with a barrel that genuinely seems to turn transparent depending on the light.

After spending time with it, this is a pen that surprises in stages. It looks striking, it feels unusual in the hand, and it writes in a way that sets it apart from most gel pens at any price.

First Impressions: A Barrel That Seems to Vanish

The Zoom L1 arrives in a stylish triangular prism box, shared across the three new Zoom releases, with a test-writing sheet and warranty card inside. Color options include Silver Full Black, Graphite Blue, Matte Blue, Matte Brown and Matte Grey, six finishes in total, and this example is the Silver.

The barrel looks like ordinary silver at first glance, but it is not. Under certain lighting or viewing angles it appears to become transparent, and you can see straight through it. The effect comes from Durabio Bio Engineering Plastic developed by Mitsubishi Chemical, arranged in a double-layer structure: a silver inner barrel inside a clear outer layer. Where light reflects, the barrel reads as thicker; with no reflection, only the inner barrel is visible.

The barrel is also described as scratch-resistant and impact-resistant, so the trick is not purely cosmetic. The center ring is ABS resin, the cap is aluminum, and the clip is zinc die-cast with a movable design that flexes softly rather than resisting. The grip section and mouth ring are finished in matching black elastomer and resin, keeping the palette unified.

The Cap: Quietly Satisfying

The cap opens with a light touch and an unusually smooth, pleasant feel. It closes with a soft click and seats firmly, with no looseness. That combination of low effort and clean feedback is rare, and it is one of the details that makes the pen feel considered rather than merely pretty.

One caveat: the cap can be posted on the back, but it sits loosely and will fall off if the pen is tilted, so posting is best avoided. The pen is well balanced without posting anyway.

The Refill: Gel Ink with Line Variation

The Zoom L1 uses a 0.5mm tip only, with a newly developed water-based gel refill sold under the BNZKE designation. At purchase you choose between black and blue-black ink; this one was bought in blue-black.

Where the Zoom C1’s oil-based refill enlarged the ball seat, this gel refill shrinks the ball seat by 93 percent. The practical result is that writing upright produces a finer line, while writing at a lower angle produces a thicker one, giving something like the pressure variation of a fountain pen. The refill is also compatible with the Zoom C1’s oil-based refill, so the two can be swapped.

On paper, the writing feel is smooth and light, and the line does visibly widen when the pen is laid down. It is an odd, satisfying sensation that few ballpoints or gel pens offer.

Everyday Handling: Grip, Weight and Balance

The Zoom L1 measures 140mm in total length and weighs 22g, with a grip diameter of 10.3mm. The center of gravity sits low, moving to roughly the middle of the pen when the cap is posted.

The silhouette is reminiscent of the classic Zoom 505, which will resonate with anyone who remembers that design. The wavy texture on the grip section is subtle, with no engravings to break up the surface, and the tactile quality of the materials is excellent throughout.

For writers who prefer a heavier pen, though, 22g may feel too light. There is genuine comfort in the lightness over long sessions, but stability when writing is a matter of preference, and heavier pens can offer more of it.

What We Liked

• Attractive, distinctive design
• Well-balanced weight distribution
• Pleasant texture and easy grip
• Smooth, comfortable writing feel
• Light and fatigue-friendly over long sessions
• An excellent refill with real line variation
• Satisfying cap feel

Things to Consider

• The very light weight may not suit writers who prefer a heavier, more stable pen
• The cap posts loosely and will not stay attached, so avoid posting it
• Only a 0.5mm tip is offered

Buying Advice

The Zoom L1 suits anyone who wants a distinctive capped pen that writes with a light touch and rewards attention to detail. The refill alone, with its upright-fine, laid-back-thick line behavior, makes it worth trying if you enjoy gel inks with character.

If you prefer a heavier pen with more planted stability, the older Zoom 505-style writing feel may still be your preference, though the L1’s refill is arguably the better of the two. At 4,400 yen including tax it sits in accessible premium stationery territory, and the transparent-barrel effect is worth seeing in person.

Conclusion

The Zoom L1 is a pen that surprises more than once: visually with its light-reactive double-layer barrel, tactually with its smooth cap and comfortable grip, and on paper with a genuinely clever gel refill. For lovers of well-made pens, it is an easy recommendation, and the two sibling Zoom releases are worth checking out as well.