on saleTWSBI Classic Fountain Pen - Sapphire

Product Code TW-M7443680

In Stock

out of stock

on saleTWSBI Classic Fountain Pen - Sapphire

Product Code TW-M7443680

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 Classic comes with a benchmark piston ink-filling mechanism and has all detachable parts. Similar length but slimmer than its sister pen, the Diamond 580. This fountain pen has a glossy blue finish with an ink window and a stainless steel nib. It unscrews to open and the cap posts onto the barrel.

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.

Warning: this pen should not be cleaned with any form of alcohol or acetone, or it will break down the plastic used in the pen.
Fountain Pens

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
Fine, Medium
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
13mm (0.51in)
Diameter - Cap (without clip)
12mm (0.47in)
Diameter - Cap (with clip)
15mm (0.59in)
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.

126mm (4.96in)
Length - Cap
60mm (2.36in)
Length - Nib

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

19mm (0.75in)
Length - Overall (Closed)
137mm (5.39in)
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.

163mm (6.42in)
Weight - Body

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

16g (0.56oz)
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 48 reviews
Underrated Pen

Great pen and great service as always! Ive always liked the classic but hadnt bought one because of some of the negative reviews Id seen on it. The large step to the grip doesnt bother me, but I can see how it would bother others. I dont typically post pens so the addition of the o-rings on the filler **** doesnt really change much for me. It does post but doesnt feel as secure as my ECO. My only issues with the pen is that the plastic sleeve on the grip moves slightly while you write, and when capping the pen you have to really tighten it to get the facets to line up. Other than that its a great pen that seals well, writes smoothly, and looks good.

Mark F.

I love all Twisbi and this one is no acception. It's smooth writing and does not dry out.

Silas K.
Very nice pen. Especially for the $$.

Very comfortable to use. Writes better than any other pen I own. Instructions that came with it are inadequate. They show you how to disassemble it, but not really how to use it. Once you figure it out, then you can look at the instructions and say, Oh, that's what they meant! I think mine may be damaged from initial attempts to fill with ink, so now it will only fill with enough ink to write 1/2 page and then have to refill.A really great pen, particularly for the price. Writes better than pens priced 6 or 8 times as much.

Michael R.
Very functional

It's a good pen. The filling process was very good, and without drama (which, in my experience, is not always the case with piston-fillers). The nib is quite rigid, so you don't get much variation of line, but it's completely reliable.

Mid-range TWSBI pen; plastic does not last forever

As a long-time fan of TWSBI pens, I was happy to receive this pen as a birthday gift 6 years ago. I've used it since for a lot of journaling and composition, and it has been a pleasure to use. A year or two in, the cap broke where the metal and plastic parts join; this was due to how I was carrying it in my bag. I was able to repair it with super glue, and the fix was not noticeable. After about four years, the piston stopped sliding easily, because the rubber seems to have degraded, in spite of (or possibly because of) regular application of silicone grease and use of lubricated ink. I switched to removing the feed and refilling it with a syringe. This process almost always resulted in a bit of ink leaking between the feed and grip, and I would often end up with inky fingers after using the pen. This problem increased over time, so I would use it less and less, especially when in the office, where inky fingers is not professional. Finally, just recently, after six years, the plastic piece that holds the feed but is beneath the grip broke, and the pen is not reparable without replacing the whole nib assembly. Because the piston is also not working , rather than repair, I plan to retire the pen. This was my third, and probably final, TWSBI pen. I love how they disassemble and are accessible to a mechanical nerd like me. But the plastic construction has always proven to be the weak point, and each one has disintegrated as a result of the material choice. Time to find something more durable.

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.