on saleTWSBI ECO Fountain Pen - Glow Green

Product Code TW-M7449110

In Stock

out of stock

on saleTWSBI ECO Fountain Pen - Glow Green

Product Code TW-M7449110

In Stock

out of stock

Nib Guide

Not sure which size nib is best for you?

Try our Nib Nook tool to view and compare nib widths using our writing samples. Learn more ›

The TWSBI ECO fountain pen boasts an incredible value with its piston filling system and affordable price. Like many other TWSBI fountain pens, it features a crystal clear acrylic barrel so you can see your ink level, and a green cap and piston knob that both glow in the dark! The pen cap has an inner cap to ensure a perfect seal when stored away. It is completed with silver trim and a silver stainless steel nib.

TWSBI’s belief is that it is important to allow the user to disassemble and reassemble the pen and completely experience the traditional aspects of owning and using a fountain pen. These pens also come packaged with a wrench and silicone grease. Neither of these accessories are intended to be used immediately, as they are for long-term care and maintenance. Additionally, please use extra care if you choose to disassemble the nib and feed, as the feed is very fragile.

Fountain Pens
Green, Clear

Whether or not the barrel of the pen is translucent, allowing you to see the ink and filling mechanism inside.

Body Material
Cap Rotations

For pens with a screw-cap closure, how many rotations it takes to uncap/recap the pen.

Cap Type

How the cap is opened/closed from the barrel of the pen. Some common options include Snap-Cap, Screw-Cap, Magnetic Cap, or Capless (no cap).

Compatible inks & refills

Which ink this pen will accept. Choices include bottled ink and various styles of pre-filled ink cartridges.

Bottled inks
Filling Mechanism

How the pen fills with ink. Click here to watch our video tutorial on common filling mechanisms.

Grip Material
Nib Size
Extra-Fine, Fine, Medium, 1.1mm Stub
Nib Color
Nib Material

Whether or not the cap fits securely onto the back of the barrel when open.


Whether or not the nib/tip can retract into the body of the pen (usually for click or twist-open style pens).

Diameter - Body
12.8mm (0.50in)
Diameter - Cap (without clip)
14.9mm (0.59in)
Diameter - Cap (with clip)
17.3mm (0.68in)
Diameter - Grip (mm)

Measured from the place most people choose to rest their fingers, which varies with each pen.

Length - Body

The measurement from the back end of the barrel to the tip of the nib.

131.6mm (5.18in)
Length - Cap
60.4mm (2.38in)
Length - Nib

The measured length of the visible portion of the nib when it is installed in the pen, from grip to tip.

18.5mm (0.73in)
Length - Overall (Closed)
138.8mm (5.46in)
Length - Overall (Posted)

When the cap of the pen is posted onto the back of the pen body, this is the measurement of the entire pen including the nib.

167.5mm (6.59in)
Weight - Body

If a converter is included with the pen, this weight is reflected in the total.

13g (0.46oz)
Weight - Cap
8g (0.28oz)
Weight - Overall (g)
Max Ink Capacity - Piston Vac

The maximum volume of ink that can fit in the pen when using the built-in piston or vacuum filling mechanism.


Customer Reviews

Based on 61 reviews
Alvaro M.
Good pen

This is my first Twsbi pen, is a good pen, well made, looks big, it works good but personally I was expecting a softer writer, I’ve read lots of amazing comments about how soft is write with it, but personally isn’t, works good but is not softer than other pens.
I bought this pen to use shimmer inks and it pen works great with shimmer inks even with the F nib, I think this is the hight value of this pen,

Btw the glow effect is great.

Glow doesn't last very long

I like Twsbi's. I'm too cheap (and will drop them or lose them anyway) to buy the super fancy $200-$2,000 pens so the ones with gimmicks are appealing (e.g. the magnetic Monteverde is a new favorite!). The glow in the dark Twsbi was in line with my gimmick-ness need. Well, the glow in the dark part doesn't really last that long. After 8 min the glow is sort of there where you can tell it's a glow pen. I get 34 min max with the (high glow to I can sort of see it glow) glow with an all day in the sun and a boost with my ultraviolet flashlight. Besides that the pen is great and behaves like all Twsbis.

Molly C.
I love TWSBI ECO Pens

I use this primarily for urban sketching. I have three of these pens with different nibs. I live in the desert where the humidity is very low. This pen stays wet even when I'm in the hot sun. Many other fountain pens I've tried dry up while I am drawing so I end up with skips and frustration. Not so with the TWSBI Ecos.

Jesse P.
Love it

New favorite for sure, I love that TWSBI came out with a glow in the dark pen!

Extra fine nib review

I am a big fan of the Eco's massive ink capacity and ink filling ability. I like how I can take a syringe and take almost a full 2ml sample and place it into the pen reservoir. There is a lot to like about this fun pen. I just have one reservation.. It is not possible to buy a different sized nib if you want to have multiple nibs, or if you don't prefer the one you purchased. If you do not like it you will have to buy a new pen and harvest the new nib, and if you even like it, to use. One solution is to watch YouTube to see how different sized nibs perform and hear how they feel. I purchased an extra find nib on accident, I meant to purchase the fine nib, but it was a Christmas present so that got lost in translation. After a week of using it and comparing it to my Pilot Metropolitan I found that the scratchy extra fine nib was less scratchy and enjoyable to use. I enjoy that the ink flow is quick and variable. What I mean by that is that the pen will just bleed ink if you write too slow. This kind of messed up my writing but I'm trying to write slower with less ink. Interestingly if I go too fast the pen cannot keep up. So if you are a fast writer, this might not be the pen for you. The grip is much better than the Metropolitan and I don't get ink all over the place. I thought I would also see less bleed through on my notebook, but it can actually bleed through paper more since it has a harder press down on the paper I suppose.

FAQs about Fountain Pens

How do I fill a fountain pen with ink? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

It depends on the pen's filling mechanism, which you can find in the Technical Specs section above. 

Here's a quick definition of the most common filling mechanisms:

  • Cartridge - A small, disposable, sealed plastic reservoir that holds fountain pen ink. These come pre-filled with ink, and typically you just push to insert them into place and you'll be ready to write! Check out our quick guide here.
  • Converter - A detachable and refillable ink reservoir that allows you to use bottled ink in a cartridge-accepting pen. Typically you will install the converter into the grip section, dip the nib/feed into the ink, and twist or pull the converter knob to draw ink into the converter. Here's a video for how to fill a cartridge/converter pen using a LAMY pen as an example.
  • Eyedropper - A pen that utilizes the entire barrel as a reservoir for ink. Ink is directly filled into the barrel, allowing for a high ink capacity. Here's a video on how to do it!
  • Piston - A type of filling system that uses a retracting plunger inside a sealed tube to draw ink into a pen. They are typically either twist or push-operated. These pens cannot accept cartridges or a converter, and only fill from bottled ink.
  • Vacuum - A push-style piston that uses pressure to fill the large pen body with ink. They seal the ink chamber when closed, making it ideal for flying without risk of leaking. Check out our video on how to use a vac filler here.

Check out more info on these filling mechanisms including a video on how to fill each one on our blog.

How do I clean a fountain pen? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

It depends on the filling mechanism, but it mostly comes down to flushing it out with water, and sometimes a little bit of Pen Flush if the ink is really stuck. 

It's a bit easier to show than to tell, so we've put together a few quick videos showing you the process:

How often do I need to clean my fountain pen? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

We recommend a good cleaning every 2 weeks, and any time you change ink colors. 

Water will usually do the trick, but we recommend you use our Goulet Pen Flush if the ink has been left in the pen for a while and could have dried up, or when you’re switching ink colors.

My pen won’t write! What do I do? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

First things first... make sure you have ink in the pen! Be sure that the ink cartridge or converter is seated properly in the pen, and that you aren't out of ink.

We always recommend you give your pen a good cleaning first, using our Goulet Pen Flush, or a drop of dish soap in some water. New pens often have some machining oil residue left in the feed, so a good cleaning often does the trick first.

If that still doesn't work, try priming the feed. This consists of either dipping your pen nib and feed in ink, or forcing ink from the converter down into the feed. 

If it’s still not working after that, please reach out to us so we can help! 

What's your return policy? 8EDA1617-F73A-4DAF-8245-6D2BF4ABEB7B

You can submit a return request within 30 days of your order date. You can read all our Return Policies here.

To initiate a return, please submit a request at the Return Portal. Our Customer Care team might reach out to you for more information.

Please note we are unable to accept a return of any Namiki or Sailor Bespoke fountain pen for any reason once it has been used with ink. Please thoroughly inspect and dry test the pen before use.