Sunstar mute-on Review: A Gel Pen With 33% Less Knock Noise and Poetic Colour Names
Sunstar Stationery's mute-on is a quiet gel ballpoint that tones down the "click" of the knock. It is aimed at anyone who has winced at the sound of a pen in a meeting, a library or a quiet desk at night. This article gathers only what could be confirmed from news reports and the maker's announcements.
What is the mute-on?
According to Impress Watch, it went on sale in late April 2023 for 264 yen. Sunstar says the knock sound is about 33% lower than its earlier products. The ink is a fast-drying gel in black only, the barrel is triangular, and the body is described as 149 x 13 x 11 mm.
How quiet is it really?
Lifehacker Japan reports a measured level about 20 dB lower than an ordinary ballpoint, and 10 to 15 dB lower than other quiet pens, with only the faint rub of plastic parts left. That is one outlet's measurement, though. The articles I could check do not explain how the noise is reduced, so I can't say what the mechanism is.
You can't pocket it with the tip out
While the pen is knocked out, the clip is retracted. The idea is to stop you from slipping it into a breast pocket or notebook with the tip still exposed. So beyond being quiet, it also guards against a small everyday slip.
Colour names like little poems
Each muted barrel colour has a poetic name. The first batch of eight:
| Name (translated) | Barrel colour |
|---|---|
| The Night-Owl Cat | Black |
| The Dozing Whale | Navy |
| Midwinter Star | White |
| Sepia Afternoon | Beige |
| Early-Summer Drop | Violet |
| Bottle on the Beach | Mint |
| Dawn Cherry Blossom | Pink |
| The Elephant's Sleep-Talk | Grey |
Per Sunstar's announcement, eight new colours followed in early August 2025: White Rabbit on the Snowfield (white), Cloudy Town (grey), Dreaming Cat (black), Scent of the Cafe (brown), Rainy Lilac (violet), Sleeping Forest (green), Magic Carpet (pink) and Quiet Daybreak (blue). They cost 330 yen each including tax.
In PencilDB
PencilDB records the first batch as Sunstar mute-on gel ballpoint and the new colours as mute-on, second batch, eight part numbers each.