Compiled from 11 sources; we haven't tested this product ourselves yet. How we research
Quick answer
The Pentel Aquash Water Brush is a nylon-tipped brush with a squeezable barrel that holds water, so you can paint with watercolor pans, pencils or markers without a water cup. The medium FRH-M is 155 mm long capped and holds 7.5 ml, per JetPens. Pentel makes five tips, from small to flat.
On this page10 sections
The Aquash medium water brush, 155 mm capped (1 mm = 5 px).
Product facts
Product
Pentel Arts Aquash Water Brush, Fine Point Medium (FRH-M)
Soft translucent plastic barrel; nylon brush tip (Pentel)
Price range
$$$5–20 per item
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Notes on these facts
Made by Pentel Co., Ltd. (Tokyo). Made in Japan: The back of the export package (XFRH-MX) shown in the Amazon listing's photos is printed "PENTEL CO., LTD. TOKYO JAPAN" and "MADE IN JAPAN". Pentel's US and Japanese product pages don't state a country. Source. Price: example listing.
Price bands are typical US retail, checked October 2026. Conversions to US dollars are approximate, at October 2026 rates (US$1 = ¥158 = ₩1,330 = NT$32.5 = CN¥6.7 = SEK 9.9 = DKK 6.7 = ₺49.6 = C$1.41 = A$1.43 = CZK 21.7; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).
Key takeaways
Pentel Japan lists five tips: large FRH-B, medium FRH-M, small FRH-F, mini medium FRH-MM and flat medium FRH-MH.
The medium tip is 3.75–4.1 mm wide and 12.5–14.5 mm long, per Pentel Japan; the flat tip is 6.0 mm wide.
JetPens lists the medium at 15.5 cm (6.1 in) capped and 7.5 ml of water; the compact mini holds 5.5 ml.
In Japan, Pentel now sells the brush as the Vistage みず筆 (water brush); the medium lists at ¥429 (about US$2.70) with tax.
The US package printed in Amazon's listing photo reads "Pentel Co., Ltd. Tokyo Japan, Made in Japan".
What is the Pentel Aquash Water Brush?
It’s a paintbrush with a built-in water tank: a soft, squeezable barrel feeds water to a nylon tip, so you can paint without a water cup. You touch the wet tip to a watercolor pan, a watercolor pencil line or water-based marker ink, then spread or blend it.
Pentel’s US pages describe a valve system that limits leaks and lets you control the flow, a translucent barrel so you can see the water level, and a flattened barrel that won’t roll off the table. Pentel says the brush is ACMI-certified and works with solid colors, powdered pigment, watercolor crayons, markers and pencils.
The name goes back to Pentel’s Aquash watercolor pencil set of 1997, which came with a water brush and won a Good Design Award in 2000, according to Pentel’s design archive.
Which tip sizes does the Aquash come in?
Five: large, medium, small, a mini-bodied medium, and a flat medium. Pentel Japan publishes each tip’s width (a) and length (b):
Tip
Pentel code
Width × length
Japan price with tax
Large
FRH-B
5.2–5.6 × 17.0–19.0 mm
¥605 (about US$3.80)
Medium
FRH-M
3.75–4.1 × 12.5–14.5 mm
¥429 (about US$2.70)
Small
FRH-F
2.4–2.8 × 9.0–11.0 mm
¥429 (about US$2.70)
Mini medium
FRH-MM
3.75–4.1 × 12.5–14.5 mm
¥363 (about US$2.30)
Flat medium
FRH-MH
6.0 × 14.0–16.0 mm
¥605 (about US$3.80)
The five tips at 1 mm = 9 units; the mini uses the medium tip on a shorter body.
In Japan, Pentel also sells a slim type (XFRS-M, 3.7–4.1 × 11.5–13.5 mm) that it says makes the water flow easier to control. Pentel says its tips use its own nylon, the kind also used in cosmetic brushes, which holds water well and resists wear.
Pentel Aquash medium specs
Spec
Aquash Water Brush, medium (FRH-M)
Tip
Nylon, 3.75–4.1 mm wide, 12.5–14.5 mm long (Pentel Japan)
Length
15.5 cm (6.1 in) capped; 14.6 cm (5.7 in) uncapped (JetPens)
Capacity
7.5 ml (JetPens)
Weight
about 9 g (Amazon)
Barrel
Soft, squeezable, translucent, flattened
US code
FRHMBP (single pack)
JAN
4902506125026
Made in
Japan (package)
Pentel doesn’t publish a length or capacity on the pages we read, so those come from JetPens. JetPens lists the compact mini at 12.6 cm capped and 5.5 ml.
How do you fill and clean the Aquash?
Unscrew the front section, fill the barrel with water, screw it back firmly, and squeeze gently as you paint. That’s how Pentel Japan describes it.
To clean the tip between colors, squeeze out a little extra water and wipe the brush on a tissue until it runs clear. Pentel’s US page for the flat tip says the brush is easy to clean, even calling it dishwasher-friendly.
It’s one of the best-known water brushes on Amazon US. On October 21, 2026, the fine-tip listing showed 4.8 stars from 965 ratings and 300+ bought in the past month, and a 3-pack of assorted tips showed about 2,800 ratings.
It’s in our $$ band ($5–20 per item) when bought singly; multi-packs work out cheaper per brush.
Where is the Pentel Aquash made?
In Japan: the export package shown in the Amazon listing reads “Pentel Co., Ltd. Tokyo Japan” and “Made in Japan”. Pentel’s US and Japanese product pages don’t name a country, so we rely on the printed package.
Frequently asked questions
What is a water brush?
A brush whose hollow barrel holds water. Squeezing the barrel wets the nylon tip, so you can activate watercolor pans, watercolor pencils or water-based markers without a cup of water.
Which Aquash tip size should I buy?
The medium (FRH-M) is the all-rounder. Pick the small (FRH-F) for details and lettering, the large (FRH-B) or flat (FRH-MH) for washes, and the mini (FRH-MM) for a pocket kit.
How much water does the Aquash hold?
JetPens lists 7.5 ml for the medium and the flat brush, and 5.5 ml for the compact mini medium.
How do you fill a Pentel Aquash?
Unscrew the front section, fill the barrel with water from a bottle or tap, and screw it back on firmly, Pentel Japan says. Then squeeze the barrel gently while you paint to feed water to the tip.
How do you clean an Aquash water brush?
Squeeze out extra water and wipe the tip on a tissue or paper towel until it runs clear, as Pentel Japan describes.
Can you put ink in an Aquash water brush?
Pentel's US page says you can fill the barrel with water or an ink wash. The Aquash package itself is printed "Only for use with water", so check before filling it with anything else.
Is the Aquash the same as the Pentel Vistage water brush?
Yes. Pentel Japan sells the same five FRH tips as the Vistage みず筆, and JetPens now lists them as Vistage water brushes, formerly Aquash.
