Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition
Sumi - Flex Fountain Pen, Black Edition

Sumi - Flex Fountain Pen, Black Edition

14 reviews
Regular price £115.00
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"Game-changing!" Sumi - The Flexible Fountain Pen

(Sumi pens are made to order so please allow 1-2 weeks before dispatch)

Why isn’t there a fountain pen that writes like a calligraphy pen with no need to dip it in ink?  This is the question I asked myself three years ago. It seemed no one had a good answer so I set about answering it myself.  And after a pile of prototypes, failed experiments and a lot of head scratching, I’m very proud to introduce you to Sumi - The Flexible Fountain Pen!

"Tom has done it again! I mean...just look at it! This is his new fountain pen that has a flexible fine nib which means you can have your thick and thin lines without having to dip your pen in ink every so often!"

Hazel's Lettering (professional calligrapher)

The Sumi's secret ingredient is the custom, super-flexible nib which allows you to write as thin as 0.4mm, and up to 2.0mm when fully flexed. It’s also tipped with a German iridium tip for a smooth writing experience (no more scratching or ink splatters) and, unlike standard calligraphy nibs, it will last a lifetime.


It's springy, fun to use and incredibly addictive!

The Sumi pen comes with an ink converter (a fancy re-fillable ink cartridge) which means you can use the pen with 100s of different coloured fountain pen inks. I highly recommend using Diamine Inks which have been specifically tested for use with the Sumi pen. They’re lovely and juicy and even have a metallic colour range which shimmers in the light! We do not recommend using ink cartridges with the Sumi pen as the ink flow will not keep up with your writing and is likely to result in 'rail roading'. 
Just as the function of the pen honours calligraphic heritage, the form is also inspired by a traditional quill and ink set. I’ve paired the design back and have also infused the aesthetics with a minimalist Japanese look (hence the name Sumi which means ‘ink’).  The making of the pen is a different story, and is firmly rooted in the 21st century. By using state of the art CNC watchmaker’s lathes I can create a supremely refined and well balanced pen.
shimmer ink in a fountain pen
A big question (which, as a designer I often grapple with) is this: ‘We are all individuals so why are the products we use on a daily basis so often utilitarian and say so little about us and our own individuality?” It’s the reason I wanted to create a pen which is as unique as its owner. So I spent a lot of time developing a new dyeing process taken from fine jewellery production techniques.  Every pen is individually dip-dyed by hand using this technique, making each one subtly unique.

Sumi - Flexible Fountain Pen, designed to celebrate creativity, craft and individuality. 

Good to know & FAQs:
  • The brass stand has been designed to be equally happy standing on your desk, or in your bag on the go.

  • The Sumi pen works beautifully with all Diamine Inks (including shimmer!) You can find them here).  Be sure not to use calligraphy specific ink as this can clog the pen.

  • BONUS, Want to use your Sumi as a creator pen?  No problem, you can find the attachment here.

  • Like a good pair of leather shoes the Sumi Pen will soften and become even more flexible with use. It will adapt to your style of writing and become unique to you. As such, it may take a little time for your pen to ‘settle in’. If you have any questions at all about the functionality of your pen, please get in touch as we are always very happy to help.

  • It is designed to compliment your calligraphy pen and not replace it entirely. If you're looking for the maximum softness and flex please take a look at my Flourish Pens.

  • Measures 165mm with brass stand, 150mm without and weighs 67g with brass stand, 25g without.

  • Each pen is beautifully presented in a gold foiled gift box.

  • Every pen is machined from solid metals on a lathe used for making fine watch and aerospace grade components, so you can be sure your pen will write perfectly for years and years to come.

  • Brass naturally develops a patina over time and with use. You can choose to embrace this unique change or use our Brass Polish to bring it back to its gleaming best.

  • We offer a complimentary repair service, so should your Sumi pen need a little TLC please contact us.

  • We Ship Internationally.
  • Your order will be shipped within 48 hours when in stock, please refer to lead times of the product you are buying, as some handmade / hand dipped products may take longer until we send them.
  • All UK orders are shipped free over £60 using Royal Mail and there is a tracked or special delivery option so you can track them as they leave us. For International orders we use the Royal Mail’s Airmail service. Again, you can track them along the way.
Customer Reviews
5.0 Based on 14 Reviews
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tomsstudio Sumi - Flex Fountain Pen, Black Edition Review
Beautiful pen and great service!

The pen looks amazing and writes beautifully! It’s a bit stiff, but I need to write with it more. I’ve been looking for a modern flex fountain pen and I think I found the perfect one! ♥️ The service by Tom’s Studio is also amazing. When my package arrived, the package had been opened and the pen was missing. I contacted Tom’s Studio right away (I also sent pictures of the package) and they sent me a reply the following day. They wrote that they’d sent me a new pen and the pen arrived within a week. A big THANK YOU to this amazing group of people. The service is fantastic. I will definitely enjoy writing with my beautiful pen!!

Osina S.
Netherlands Netherlands
Sumi - Flex Fountain Pen, Black

I’m a art director in branding and am looking to feel passionate again about what I do. I look at amazement at those who have the skill and craft to draw beautiful characters and words. Calligraphy gives me an opportunity to learn a new skill and to get out of the computer. This pen is beautiful, if feels balanced to hold and flows with ease. The design craft in its making made me choose it amongst all pens on the market. I am extremely excited to start in this journey of calligraphy- with beautiful tools and lots to learn it will certainly be fun !

Debra J.
Australia Australia
Great quality

I'm used to using flex nibs in an oblique holder so it took a bit of time to get used to the straight pen, but the pen and nib are sturdy and write smoothly. It also looks great.

Nabihah G.
United Kingdom United Kingdom
A good find.

The pen looks great and works well. Buying it was easy too. My only reservation was about the decorative box it came in. The overall character of the pen is thoughtful engineering, which the gold pink and blue of the box does not echo. Trivial perhaps, but I hope my comment is helpful.

United Kingdom United Kingdom
Fine & reliable modern flex pen

I was expecting a larger nib, for extra wide lines. So I was perplexed when I first uncapped this delicate pen and saw the smallish nib. But I inked it up with some Diamine Dragon Blood and started putting it to work. No clogs from the shimmering ink. No railroading. No nib starving from the feed. No tinkering. No fuss. No nonsense. The nib may be a bit small and it may be a wee bit stiff, but it's a real joy to write with! It's the flex nib pen I reach for when I just want to write something quick and beautiful. It's thoroughly reliable, and I'm loving it more and more each time I use it. Thanks Tom!!!

Philippe M.
Canada Canada

Why Tom's Studio

Values & Craftsmanship

Tom still uses the same design principles as the very first pen he made for his wife. It's important to him to create products that his customers will cherish for the rest of their lives. It's why each every one of my products has a lifetime guarantee.

 "Have nothing in your house that you do not know to be useful, or believe to be beautiful." William Morris

Creativity Tools

Tools of the past were made by master craftspeople that cared passionately about their craft and the experience of the people using their products. We seem to have lost the 'soul' of these tools in the age of mass production. It's my mission to bring the creative soul back to the tools we use every day.

"Creativity is contagious, pass it on" Albert Einstein

Tried and Tested

Seeing his calligrapher wife, Gemma Milly, using a mass-produced calligraphy pen inspired Tom to craft a collection of pens that matched the high quality of her work. Using a 60-year-old engineering lathe, he now makes pens for some of the world’s most celebrated calligraphers and stationery brands.

"Beauty Is The Harmony Of Purpose And Form." Alvar Aalto

A Labour Of Love

From the first pen I made for my wife to the pens I now make for my customers around the world.  I put the same care and attention into each and every pen.  I love what I do and hope that it shows in the finished product.

old fashioned lathe