TWSBI Brand Overview

TWSBI fountain pens lined up on a notebook

TWSBI is firmly established in the fountain pen community, known for piston-filled pens, usually in some form of a demonstrator fountain pen, with an extremely reasonable price. And while they may seem somewhat newer to the pen scene, they’ve actually been in the business longer than most people realize. 

TWSBI history/background

TWSBI (pronounced twizz-bee) started out well over 50 ago as Ta Shin Precision, an OEM or Original Equipment Manufacturer making parts for different brands around the globe, both in the pen world and in other industries such as toys. As a multi-generational family business, they decided a decade ago to evolve their strategy and design their own complete pens and start selling under their own brand name. Thus TWSBI was born.

The creation of TWSBI's name takes a little explaining, it’s essentially an acronym. It stands for the phrase "Hall of Three Cultures" or "San Wen Tong" in Chinese. The character "Wen" translates into language and culture. The phrase "San Wen Tong" also brings to mind the Hall of the Three Rare Treasures created by Emperor Qianlong as a memorial to three great masterpieces of Chinese calligraphy. The initials of the phrase "San Wen Tong" was reversed and thus turned into "TWS". The last letters "Bi" was added with its literal meaning of "writing instruments". Thus combining the two, creating TWSBI. So, it’s a bit complex but essentially it’s an acronym that honors writing instruments and masterpieces of Chinese calligraphy. 

What makes TWSBI pens special

Ever since they started producing its own line of pens, TWSBI has been focusing on a few key areas across their product line. They want high build quality, good value for the price, clean design, writing enjoyment, and user serviceability. 

Build quality

The build quality TWSBI’s especially known for includes pens with excellent cap seals with inserts that keep the nib wet and ready to write at a moment’s notice. They use high-quality resins and have proprietary treatment methods for them on models like the 580 to get high clarity and scratch resistance. The fountain pens have excellent cap seals, high-quality plastics, and are equipped with reliable German nibs.


For a decade now, TWSBI has made some of the most affordable, best performing piston and vacuum filling pens in the world. Their entire regular range goes from $18.99-$80, with some stellar pens in the sub-$50 pricing that gets them into the hands of many newer FP users. Comparable pens from other brands may run 2-3 times the price, but TWSBI streamlines their operation and distribution and intentionally keeps their margins lower so they can get pens of high value into your hand. 


TWSBI is known primarily for piston fill demonstrator pens, a clean, polished look, and intentional packaging. Several models have had a multitude of special edition colors which makes them quite collectible.

Writing enjoyment

All of their regular pens use stainless steel nibs, with a wide range of nib sizes from EF-B and stubs for a lot of variety. The sizes of nibs range from standard #4 to #6 sizes, with many nibs swappable. Some models even have replacement nibs/grips available so you can extend the utility of a single pen. They’re known as workhorse pens, ready for daily carry use and heavy writing for students, working professionals, and creatives. 

User serviceable

Every pen comes with a wrench and silicone grease along with instructions for disassembly/reassembly (though videos help!). This is very atypical with fountain pens today and was pretty trailblazing when TWSBI first came on the scene.

TWSBI fountain pens with various colors of ink inside

TWSBI Models

Now let’s do a grand tour of the different TWSBI fountain pen models currently available in North America. I’m going to skip over past limited editions or iterative variants that are no longer available as that can get pretty confusing.

So going from most affordable to most expensive, here are all the TWSBI models.



Three TWSBI GO fountain pens

The TWSBI GO is their most affordable pen and is meant to be a bang-around every day pocket pen. The look of this model diverges a bit from most of the other TWSBI line because the resin is less translucent and is made of a slightly softer resin. On the plus side, it’s quite durable and makes for a good “throw-in-your-bag” pen. 

It has a unique spring-loaded push-piston filling mechanism that can hold more ink than your average pen (1.61ml max). It’s a snap cap w/ roll stop, no clip on this pen which you may or may not love.  The cap pushes to post on the back of the pen, and it’s a firm hold. 

It uses TWSBI’s smallest #4 size stainless steel nib in 5 different nib sizes (extra fine through broad plus a 1.1mm stub). It writes as well as pretty much all the other TWSBI pens, so its low price shouldn’t deter you. It’s not specifically advertised as being a “kid pen” but that’s what it can come across as when you look at similar styled pens from other brands like the Pelikan Twist. For that reason it’s not a wildly popular pen for us, but it’s still a solid performer. 



TWSBI SWIPE fountain pens and accessories

The TWSBI SWIPE is their newest fountain pen model and is their only cartridge/converter pen. It can actually use 3 different filling methods they designed themselves: an oversized standard international cartridge, a twist converter like you see in many other pen brands, and a spring-loaded push-piston converter similar in function to what you find on the GO. The SWIPE can take regular standard international short cartridges, but the TWSBI oversized cartridges will pretty much only fit the Swipe.

The SWIPE uses TWSBI’s #4 nib like the GO in the same 5 nib sizes. You get a snap cap and it's push to post. While it has a clip, it’s basically just for show. It’s super tight and acts more like a roll stop. I think this is another pen great for beginners, or to gift to someone who likes to tinker as they get so many different filling mechanisms to try out. 



TWSBI ECO fountain pens lined up on an open notebook

The ECO is TWSBI’s most popular pen model by volume, at least based on what we sell here at Goulet Pens. There have been a multitude of different special edition versions (check out our ECO special edition history blog here), but they all feature a crystal-clear round barrel with a high ink capacity of 1.76ml thanks to the internal piston mechanism. It has a threaded cap, push to post with an o-ring for a good posting fit. There’s also an o-ring at the back of the grip section to help seal the cap when it’s closed, making it one of the best pens made today in terms of cap sealing. 

It uses the same #4 size nib as the GO and Swipe, in all 5 nib sizes. And while TWSBI doesn’t offer any of these nibs separately, you can technically swap them between each other on any of these models by pulling out the nib and feed together. Just be careful, the fins on the feed are fragile and can break. 

What I like most about the ECO and other models with the internal piston is that they provide you with instructions and the tool to remove the piston mechanism. We’ve made other videos showing how to remove and reassemble all the models that can be taken apart, as it’s helpful to see it done on video.  However, it’s cool that TWSBI has designed their pens with this feature in mind. It’s especially great for demonstrator pens like this when you have a stubborn ink you’re trying to clean out. You can remove the piston and flush the pen with a bulb syringe or clean it out with a cotton swab when needed. They include some silicone grease too if you want to keep your piston moving smoothly inside the barrel. You don’t need to do this often, but it’s nice to have on hand when it feels like it’s lost its smooth action.

There’s a variation of this model called the ECO-T. It's pretty similar to the ECO but there are really just two differences in that the cap is more triangular instead of hexagonal, and the grip on the ECO is more of a true round shape instead of having a little triangularity like the ECO-T does. It’s not really worth fussing over the differences, I think you get a great pen either way and you should just pick whichever one looks good to you. This is a very solid pen for pretty much anyone, new or established in the hobby. 


TWSBI Classic

TWSBI Classic fountain pens

The TWSBI Classic is one of the few non-demonstrator fountain pens that TWSBI makes, so it does stick out a little bit. It has an internal piston and an ink window so you can still monitor your ink level. 

It has a threaded cap, push to post with an o-ring on the posting end like the ECO. It has the same #4 nib as the models I’ve mentioned already, in 4 nib sizes.


TWSBI Diamond 580, AL, ALR

TWSBI Diamond 580 fountain pen in clear

TWSBI’s flagship pen styling of the Diamond 580 is the heart of the brand. The 580 is an iteration of the 530 and 540 TWSBI released as their first pen design, and it’s definitely what they’re known for. The diamond facets on the barrel and cap are iconic to the brand, making the pen look more expensive than it is. The body has an internal piston mechanism and holds almost 2ml of ink, which is removable with the 8mm included wrench similar to the ECO. You also get silicone grease along with it. 

Much like the ECO, the 580 has had many special editions over the years (check out our 580 special edition history blog here), so it’s worth keeping tabs on the brand to see what they come out with from time to time, on the ECO and 580 models specifically as these have seen the most special editions. 

The 580 nib size increases to a #5 size, larger than all the previous models I’ve mentioned. It’s available in the 5 standard TWSBI nib sizes. The writing experience is still similar to the small nibs though, pretty smooth and nice flow. TWSBI has some very solid consistency on their nibs.

What’s special about the 580 in particular though, is the nib unit and grip section are removable. You can unscrew them both for ease of maintenance, for swapping nibs on other 580’s, or you can purchase nibs in other sizes if you want just one pen but with a wider range of nib options. TWSBI doesn’t have this for any of the models I’ve mentioned so far but it is an option starting on the 580. 

The cap is threaded, and while it’s technically postable, TWSBI doesn’t officially recommend doing so. It’s honestly pretty long when posted anyway, but the main issue is that when it’s posted, the cap is only grabbing onto the piston filler knob, so it could in theory unscrew the knob in use and push ink out of the pen. It’s not something I hear about happening a lot, but it could. Use your own best judgment. 

There are two variants of the 580 called the TWSBI 580AL & 580ALR that are worth mentioning here. The overall dimensions, nibs, and ink capacity are all the same as the 580, but think of it as a different “trim package” you get with these. It’s a little bump in price, but you get an aluminum grip instead of resin, an aluminum piston rod and piston housing. Hence, the "AL" name.

TWSBI 580ALR Navy Blue fountain pen

On the 580ALR, you get these aluminum components on the 580AL plus some other aluminum parts like the trim rings along the piston knob, cap finial, and center-band. The grip itself is engraved with subtle rings around the circumference of the grip, which give it a bit of texture…which is personal preference if you like that texture or not. 

It’s worth mentioning that disassembly is similar on the AL and ALR versions, but there’s a white bearing grease used on piston rod - do not use the included grease (per instructions) for either of these pens, the included silicone grease is just for the rubber seal on these. If the aluminum piston rod needs greasing, white lithium or bearing grease will do the trick, and that’s not included. 

The TWSBI Diamond 580 fountain pen has become iconic in the pen world for a reason, it’s an incredible pen and I can absolutely recommend it. 


TWSBI Diamond Mini & Mini AL

TWSBI Mini clear fountain pen

Since the 580 starts to get up there in size a little bit, TWSBI developed the Mini, which is quite simply a smaller version of the 580. The overall aesthetic is similar, but it’s much smaller in the hand and makes for a great pocket pen. You end up going back down to the smaller #4 nib but that’s fine, it writes well, though you do get the added bonus of nib swapability with available spare nibs which is nice. You lose almost half the ink capacity of the 580 by going to the mini version, but you’re still getting over 1ml, which is about double what you get with a typical cartridge/converter pen so it’s still quite adequate. 

It has a threaded cap and this pen is actually made to post, and brings about a feature I haven’t talked about yet on a TWSBI pen, a screw thread posting. It means you can secure the cap on with threading on the back of the pen, which is great security when writing. The o-ring at the threads helps keep the cap from unthreading, too. There’s a Mini AL version as well, which has similar aluminum grip and piston components as the 580AL does, at a slight premium. There are special edition colors from time to time (check out our Mini special edition history blog here), but not as frequently as the ECO or 580.


TWSBI Vac700R, Vac Mini

TWSBI Vac700 fountain pen in clear

Now for what I think are the coolest and best value pens of TWSBI’s whole lineup, the Vac700R and Vac Mini. Vacuum filling pens are not all that common among pen brands today, especially at the price TWSBI sells them. They boast large ink capacities and a self-sealing ink chamber that prevents leaks during transport. You fill them by pumping the piston up and down, which uses vacuum suction to draw ink up into the pen. When writing with them for more than a page or so, you’ll want to unscrew the filling knob and break the seal slightly so the ink can reach the feed and flow freely. TWSBI makes two vacuum filling pen models. 

The Vac700R is the larger of TWSBI’s two vacuum filling pens and has the largest ink capacity of TWSBI’s entire line (and just about any pen) around at over 2.3ml. It uses TWSBI’s largest #6 size stainless steel nib ranging from extra fine through 1.1mm stub. You get the same functionality of the removable nib/grip unit on the vac pens, and can even get spare nib units for them. 

The cap is threaded, and not recommended for posting as it gets pretty long but it’s still feasible. You get all the same cap sealing features like you do with the 580, which is really nice with such a massive ink capacity.

They’ve done a few colors over the years but currently they’re only available in clear, with a special version called Iris which has rainbow trim (which is pretty rad looking). They’re fairly large pens so perhaps not everyone’s flavor, which is why they followed up with the more compact Vac Mini.

TWSBI Vac Mini fountain pens in smoke and clear

The Vac Mini functions similarly to the Vac700R, but it’s designed as more of a pocket pen, in a similar manner as the 580 and the 580 Mini. The general vacuum filling principle is the same on the Vac Mini as the Vac700R, it’s just smaller all around and it still boasts nearly 2ml of ink capacity which you just won’t beat on a pocket-sized pen.

Like the 580 Mini, it is equipped with TWSBI’s smaller #4 stainless steel nib, and you can remove it and get spare nib units which can be handy. This is one of my favorite pocket pens for its compact size, self-sealing chamber, and high ink capacity. 


TWSBI Precision

TWSBI Precision fountain pen on a laptop

I’ll finish off the list with the other rare instance of an opaque TWSBI pen, the Precision. This is the only available model that deviates from resin, going to a brushed aluminum. The hexagonal body looks crisp, and the ink window is a nice touch so you can still monitor your ink level. It uses a #5 size nib in 5 different sizes, but doesn’t have spare nibs available for it. It just comes in the one smoky gray color which I think looks great. It has a threaded cap and pushes to post on the back like the Classic and ECO.

The Precision’s a nice looking fountain pen, and has great build quality. It’s on the newer end of their offerings so I think it’s still not on most people’s radar. It’s worth a look if you want a deviation from the typical clear-bodied TWSBIs. 



TWSBI fountain pen ink bottles and swabs

TWSBI also has their own line of ink. True to TWSBI’s form, its packaging and presentation looks great. There are four colors of larger 70ml bottles in some pretty standard colors, as well as expanded limited offerings of 18ml bottles in more vibrant colors. They don’t have any wild properties, but they’re well-behaved, easy to clean fountain pen inks in a variety of colors.

They have some ink cartridges too which are technically “standard international” because the opening fits SI pens, but it’s oversized and made to fit the Swipe, really. So it likely won’t fit most of your other cartridge pens. But they’re massive and work great on the Swipe!


TWSBI Accessories

TWSBI’s also developed some pretty interesting accessories over the years, mostly ones designed to make their pens even more functional, but others you can use with non-TWSBI pens, also. 

Diamond 50 Inkwell

TWSBI Diamond 50 inkwells

The Diamond 50 Inkwells have been around since pretty close to TWSBI’s beginning, and it’s the only regularly offered empty glass inkwell sold by a modern fountain pen company, that I know of. It looks cool and can just house your ink and fill like any normal bottle. What really makes it unique though, is that you can take the grip of certain TWSBI pens and fit it onto the top and fill through a tube without having to open the bottle itself. You can even fill certain pen converters through it, too, which is cool.


Vac-20A Inkwell

TWSBI Vac 20A ink wells

The Vac 20A inkwell is a simplified version of the Diamond 50 inkwell, made of plastic. It can also be opened and filled with any pen, but the cap on this inkwell is particularly designed to fit the Vac700R and Vac Mini. Just remove the grips, attach the pens to the inkwell, and fill away. It’s great for traveling or just getting a full filling on your vacuum-filling TWSBI pens. 



TWSBI Pipe in an ink bottle

The TWSBI Pipe is a weird/cool little device that’s designed to attach to your standard international converters or your 580-style pen bodies so you can slurp up ink through a straw when filling. It’s good for keeping your pen parts out of the ink, or for getting those last sacred drops of ink from a bottle when the level’s too low to fill like normal.



So there you go, a grand tour of TWSBI! They’re innovating all the time so they’ll surely come out with new things after this video/blog is published, but that’s what’s great about them as a brand, they’re never resting on their laurels.

TWSBI fountain pens

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