Pentel EnerGel RTX: Liquid Gel Ink, Tips & Refills

The EnerGel RTX BL77, the classic 0.7 mm metal-tip model.

Product facts

Product: Pentel EnerGel RTX (BL77, BLN75, BLN73, BLN77, BL80)
Brand: Pentel
Brand origin: Japan
Made in: Japan or Mexico^*
Material: 54% recycled plastic body, latex-free rubber grip
Released: 2001^*
Price range: $under $5 per pen (multi-packs divided by the count)

Notes on these facts

Made by ASTRUM Corporation (Tokyo), called Pentel Co., Ltd. until April 1, 2026; Pentel remains the brand. Made in Japan or Mexico: Pentel of America's 2022 product catalog gives the origin of the EnerGel RTX (BL77 metal tip and BLN73/75/77 needle tips) as 'Japan / Mexico' without saying which SKU comes from where. Retailer listings match: OfficeSupply.com lists Mexico for one RTX listing. Pentel's Japanese product page doesn't state a country. Check the package of the exact pen you buy. Source. Price: example listing. Released: Year the EnerGel line launched, per Pentel's Japanese news release of August 7, 2026. Pentel's Japanese magazine says it was sold only outside Japan at first, with Japanese sales starting in 2003. We found no separate debut date for the US RTX model.
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; €1 = US$1.12; £1 = US$1.32; CHF 1 = US$1.21).

Key takeaways

Maker: ASTRUM Corporation of Japan, called Pentel Co., Ltd. until April 1, 2026; in the US it is sold by Pentel of America. Pentel's Japanese site says EnerGel launched in 2001 and had sold more than 1.6 billion pens worldwide as of August 2026.
EnerGel RTX tip sizes: 0.3 mm needle (BLN73), 0.5 mm needle (BLN75), 0.7 mm metal (BL77) or needle (BLN77), and 1.0 mm metal (BL80).
Pentel markets the ink as quick-drying and smudge-resistant, and recommends it for left-handed writers. We have not timed it.
Every RTX is refillable: LRN3, LRN5 and LRN7 are needle-tip refills, LR7 and LR10 are metal-tip refills.
Pentel of America says the RTX body uses 54% recycled plastic, and its 2022 catalog gives the origin as Japan / Mexico. In Japan the same pen lists at ¥275 (about US$1.70) from October 1, 2026.

What is the Pentel EnerGel RTX?

The Pentel EnerGel RTX is a refillable, retractable gel pen from Pentel, the Japanese pen brand of ASTRUM Corporation (called Pentel Co., Ltd. until April 1, 2026), built around its EnerGel “liquid gel” ink. RTX is short for retractable: you click the end to extend and retract the tip, and the pen has a latex-free rubber grip.

Pentel EnerGel RTX tip sizes magnified 200 times: 0.3 mm needle (BLN73), 0.5 mm needle (BLN75), 0.7 mm metal or needle (BL77, BLN77) and 1.0 mm metal (BL80) — The four EnerGel RTX tip sizes at 200×, with the US model code for each.

EnerGel dates to 2001. Pentel’s Japanese site says the line had sold more than 1.6 billion pens worldwide as of August 2026; its magazine says EnerGel was made for export first and reached Japanese shops in 2003. The RTX is the main refillable EnerGel model sold in the US by Pentel of America, which says the body is made with 54% recycled plastic as part of its Recycology range and lists the 0.7 mm BL77 in 20 ink colors.

What does “liquid gel” ink mean?

Liquid gel is Pentel’s name for a gel ink with low viscosity: it is still a gel ink, but Pentel says it flows and dries more like a liquid ink. Pentel’s Japanese site adds that it has three times the lubricant of its usual gel ink (0.5 and 0.7 mm, Pentel’s comparison). Pentel UK describes the EnerGel formula as “smoother flowing and quicker drying than ordinary gel ink”, and says that unlike liquid-ink rollerballs it doesn’t need a regulator to control the flow, because the ink feeds straight from the refill to the tip.

Retailers file EnerGel under gel pens, so if you are comparing it with other gel pens such as the Pilot G2 or the Sharpie S-Gel, compare like with like.

Does EnerGel ink really dry quickly?

Pentel markets EnerGel as quick-drying and smudge-resistant, and recommends it for left-handed writers, but it doesn’t publish a dry time in seconds. The quick-dry claim is the main reason people pick EnerGel over other gel pens.

For how it compares with other quick-drying pens, see our best pens for left-handed writers.

Pentel EnerGel vs Pilot G2: which smears less?

The Pentel EnerGel RTX smears less than the Pilot G2 by maker claims and informal tests: Pentel markets its liquid gel ink as quick-drying, while reviewers report G2 smearing, mostly in the 0.7 and 1.0 mm sizes. Neither Pentel nor Pilot publishes a dry time in seconds, and we haven’t timed either yet.

In a 2011 blog test, Mark Dominus at leancrew.com found the EnerGel smudged only if touched within a second or two, while the G2 sometimes left smeary blobs. Our best gel pens roundup picks the EnerGel for people who smear and the Pilot G2 as the best all-round gel pen.

Pentel EnerGel RTX specs

Spec	Value
Maker	ASTRUM Corporation (formerly Pentel Co., Ltd.), Tokyo; sold in the US by Pentel of America
Model numbers (US)	BLN73 · BLN75 · BL77 · BLN77 · BL80
Tip sizes	0.3 mm needle · 0.5 mm needle · 0.7 mm metal or needle · 1.0 mm metal
Ink	EnerGel liquid gel ink
Mechanism	Retractable (click)
Grip	Latex-free rubber
Body	54% recycled plastic (per Pentel of America)
Refills	LRN3, LRN5, LRN7 (needle) · LR7, LR10 (metal)
Japan list price	¥275 (about US$1.70) incl. tax from October 1, 2026
Made in	Japan or Mexico (Pentel of America catalog)

Model numbers, tip sizes, ink and recycled content come from Pentel of America. Pentel doesn’t publish an official length or weight for the RTX in the sources we found, so we’ve left them out.

Pentel’s Japanese site sells the same pen as plain エナージェル (EnerGel) with the same codes, plus a 0.4 mm needle tip (BLN74) that is not in the US range. It lists every size at ¥275 (about US$1.70) including tax, up from ¥253 (about US$1.60) under a price revision that took effect on October 1, 2026, and EnerGel refills at ¥99 (about US$0.60). The JAN barcode of the 0.3 mm black BLN73-A is 4902506305008.

What tip sizes does the EnerGel RTX come in?

Four tip sizes: 0.3 mm and 0.5 mm with a needle tip, 0.7 mm with a metal or needle tip, and 1.0 mm with a metal tip. The letter N in the model code marks a needle tip: BLN75 is the 0.5 mm needle, BL77 is the 0.7 mm metal tip.

Needle tip (0.3, 0.5, 0.7 mm): a long, thin tube that leaves the writing point easy to see; good for small handwriting.
Metal tip (0.7, 1.0 mm): the standard cone-shaped tip. The 0.7 mm BL77 is the classic RTX.

On thin paper, such as a mini composition book, a finer tip lays down less ink and is the safer choice.

What refills does the EnerGel RTX use?

Every EnerGel RTX takes any EnerGel refill: LR refills for metal tips and LRN refills for needle tips. Pentel’s catalog says any EnerGel refill fits, so you can switch tip style.

Refill	Tip	Size
LRN3	Needle	0.3 mm
LRN5	Needle	0.5 mm
LRN7	Needle	0.7 mm
LR7	Metal	0.7 mm
LR10	Metal	1.0 mm

The letter after the code is the ink color: for example LRN5-C is blue and LR10-B is red. Pentel UK also sells an LRP7 refill with permanent ink.

How does the EnerGel RTX compare to the EnerGel Pearl and EnerGel-X?

All three are retractable pens with the same EnerGel ink, and the 0.7 mm metal-tip versions all take the LR7 refill; they differ mainly in body.

Model	US code	Body	Tips
EnerGel RTX	BL77 and siblings	Colored barrel, rubber grip	0.3–1.0 mm, needle or metal
EnerGel Pearl	BL77PW, BLN75PW, BLN77PW	Pearly barrel with metal accents	0.7 mm metal, 0.5 and 0.7 mm needle
EnerGel-X	BL107, BLN105, BL110	Transparent barrel that shows the ink level	0.7 and 1.0 mm metal, 0.5 mm needle

Pick the RTX for the widest choice of tips, the Pearl if you want the white barrel, and the EnerGel-X if you want to see how much ink is left.

For a gel pen with water-based pigment ink and a binder clip, see the Zebra Sarasa Clip.

Where is the Pentel EnerGel RTX made?

In Japan or Mexico: Pentel of America’s 2022 product catalog lists the origin of both the metal-tip and needle-tip EnerGel RTX as “Japan / Mexico”. It doesn’t say which SKU comes from where, and Pentel’s Japanese page states no country, so check the package.

Frequently asked questions

What does liquid gel ink mean on the Pentel EnerGel?

Liquid gel is Pentel's name for its EnerGel ink. Pentel says it is a low-viscosity gel ink that flows more smoothly and dries more quickly than ordinary gel ink, and that unlike liquid-ink rollerballs it needs no regulator to control the flow.

Does Pentel EnerGel ink really dry fast?

Pentel markets EnerGel ink as quick-drying and smudge-resistant and recommends it for left-handed writers. Pentel does not publish a dry time in seconds in the sources we found, and we have not timed it ourselves.

What tip sizes does the Pentel EnerGel RTX come in?

The EnerGel RTX comes in 0.3 mm needle (BLN73), 0.5 mm needle (BLN75), 0.7 mm metal (BL77), 0.7 mm needle (BLN77) and 1.0 mm metal (BL80). We found no 0.35 mm RTX model; that figure sometimes appears as a line width rather than a tip size.

What refill does the Pentel EnerGel RTX use?

Any EnerGel refill. The metal-tip refills are LR7 (0.7 mm) and LR10 (1.0 mm); the needle-tip refills are LRN3 (0.3 mm), LRN5 (0.5 mm) and LRN7 (0.7 mm). The letter after the code gives the ink color, such as A for black and C for blue.

What is the difference between the EnerGel RTX, EnerGel Pearl and EnerGel-X?

All three are retractable pens with the same EnerGel ink. The RTX is the main refillable line with a rubber grip and the widest choice of tips. The Pearl has a pearly barrel. The EnerGel-X is the lower-priced line, best known as the 0.7 mm BL107, and Pentel of America also sells it in 0.5 mm needle (BLN105) and 1.0 mm (BL110).

Where is the Pentel EnerGel RTX made?

In Japan or Mexico. Pentel of America's 2022 catalog gives the origin of the EnerGel RTX as 'Japan / Mexico' without splitting it by SKU, so check the package of the exact pen you buy.

Is the Pentel EnerGel RTX good for left-handed writers?

Pentel markets EnerGel ink as quick-drying and loved by left-handed writers, because fast-drying ink is less likely to smear under the hand. That is the maker's claim; we have not tested it.

Sources (33)

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