This Diamond 580 feels great with nice heft. It holds a ton of ink and it is quite striking to look at. However, I have had issues with it skipping since I got it. Sarah at Goulet Pens was kind enough to send a replacement nib and it worked well for about a day and now it's back to skipping every couple of letters. I believe it must be a design flaw. I am no stranger to fountain pens. I have used them exclusively for going on 3 years now. This TWSBI is my most expensive and worst performing. I have everything from disposable Pilot and Zebra fountain pens, Cross, Majohn, several Lamy's and none of them have performed as poorly. I am disappointed and honestly saddened with this purchase.

This fountain pen wrote beautifully and has been my go-to for quite a while now, but all of a sudden, out of the blue (no pun intended), when I unscrewed the cap to write, the TWSBI ban broke off the cap... I don't know what to think.

I have over 50 different quality fountain pens. This one gave me a great writing experience, but no one warned me that this could happen. What a bummer.

Differing from the ECO line, this pen is much nicer. It feels like a good entry level pen without breaking the bank.

This has been my favorite demonstrator for several months, but this morning, when I went to un-post the cap , it cracked right off at the top of the metal band :'( It's a gorgeous pen that writes beautifully, and I like to be able to SEE that the cap is sealed, as you can here; but I have to take back a star for that weak plastic.

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I've purchased 3 of these over the last 5 years. Two from Goulet and one from another vendor. The presentation and quality of the pen is good, but the nibs have all had issues. I've had misalignment, tipping cut off angle of the slit, and a baby's bottom.

Makes no sense because the Gos and Ecos I've bought have all been fine.

Love this pen. A great daily driver. Reasonable price, writes well and replaceable parts are a significant advantage

Love this pen too!

i got the clear EF; it writes beautifully, holds a lot of ink and i love the piston filling!

Love my new Twsbi! It has a nice way to it and writes beautifully. Additionally, it holds a fair amount of ink. I highly recommend.

Favorite pen. This is my go to regardless of how it’s inked. Smooth writing, strong shading, and feels good in my hand unposted.

I bought a 580 from Goulet...I don't even know how long ago and it's still my favorite pen. I started with Lamy and Kaweco pens, but I don't like the grip on the Lamy (I prefer round, not triangle) and the nibs on Kaweco pens felt oddly scratch to me, even on super smooth paper. I also wanted a pen that could hold a TON of ink because, despite enjoying playing with colors, I really just like to write in Iro take-sumi and am annoyed whenever I fill a pen with something else. I can also see when my ink level is low so I'm never caught empty.

The 580 is super durable. I toss it in my bag semi-carelessly and it's still looking nearly new. The cap *can* unscrew itself if it's jostled too much, but that's pretty rare. I like the nibs. They feel very smooth and they're juicy without pooling. No scratchy pen feel. They're just a bit flexible, so I can get some good line definition when writing in cursive.

Finally, TWSBI as a company is just great. I dropped my pen and broke the cap (luckily the rest survived). I couldn't find anywhere that sold replacement caps, so I emailed TWSBI directly and asked if I could buy a new cap for it. Instead, they asked for my address and just sent me a new cap. For. Free! Stellar customer service and a stellar pen. Whenever I wander pen stores, I can't help thinking to myself, "Yeah...but can it beat my 580 in experience, price, and customer service?" and the answer is, so far, no. Can't recommend more highly.

Beautiful pen and it works flawlessly right out of the box. It technically posts, but that makes it very back-heavy. One caution--the traditional TWSBI tools are well-hidden, but they are in the case. I own several ECOs and this pen is a nice step up.

This pen skips alot and wont start writing consistently. Its pretty much unusable. Hopefully goulet will rectify this

The twisbi diamond 580 is a wonderful pen. Feels good in the hand and is a smooth writer.
Also, to pen came quite quickly and was packaged with the famous Goulet care.

Back in the bad old days, TWSBI was the only cheap fountain pen with a piston filler. Now, there are so many better alternatives. I have 4 580s, 2 vac700s, a minivac, and a whole bunch of Ecos. Quality is unacceptable: too many cracking problems with these pens--I've never had any other fountain pen parts crack but TWSBIs. When I nicely request and pay for replacement parts, their customer service is rude. Don't do it, just get something else, there are so many great choices at the same price points.

I read many reviews, a quality pen, popular, good ratings. I made a good choice: the large reservoir, nib swap **** on/off, **** on cap, good weight, not too. and the pen is easy to clean
It's a great writer.
I saw an article about writing therapy to reconnect brain networks. It works, my motor skills have greatly improved, I can write well again.

Totally functional hold a lot of ink, easy to fill, great nib. I have extra fine and love it

Nephew gave me a fountain pen from another brand. Still breaking it in,

I purchased the pen as a Christmas present and my granddaughter likes it very much. We just need to buy ink, I didn’t read about everything so no ink was included.

An amazing pen. Writes great.

Great build quality!

Me like yes good I like lot a alot**a lot

Enjoying the pen very much thus far, one of my favorite aspects of it is how easy it is to swap out nibs. I love alternating between EF and 1.1mm stub for body and header writing. The system TWSBI has developed for that swap, and for storing the extra nibs in those nice red capped vials is amazing!

The TWSBI clear fountain pens are just beautiful. I love being able to see the inside of them, dominated by my color of ink I choose to fill it with. I love the way the light plays on the facets of the surface.

I have started using a bullet journal, and wanted a distinctive ink for that purpose. I found it in Baystate Blue, but the vehicle I had chosen for it was not the best choice. Enter TWSBI.

I had perceived a need for a EF nib in a TWSBI Diamond 580 so I got one, but I found my plans had been somewhat overcome by events. I washed the Iroshizuku Take-sumi outof it and put it away. Then my nettlesome experience with what should have been the perfect pen for BSB came about, and I cast a wondering eye on the 580. To make a long story a little shorter, my TWSBI is now stained with BSB but it is doing a fine job handling the ink and my nascent journaling. A tip of the hat to TWSBI, Noodler's Ink and, of course, Goulet Pens.

Always a pleasure to write with a TWSBI, and very easy to maintain. The nib is very smooth and wet and the pen feels like it is gliding across the paper.

This is a review on this one specific pen I got, not on the company or any other product. I received this pen in a very carefully packaged box, the unboxing experience was beautiful, you can tell Goulet employees put their love in it which I am very thankful, and I will definitely comeback if I’m buying another pen.
When I found out the issue about the pen and reached out to them I received very inspiring and practical advice.
But the pen itself is flawed, the Nib I got on this one does not line up with the tongue of the pen( it was tiled toward one side) , nib is also a tiny bit scratchy which lead to my decision of wanting to swap the nib, then I found out the head of my pen(the part that is holding the nib) doesn’t unthread. I called the customer service and yes I received very practical advices but after doing what I was told to, they situation was better —- I am able to move and rotate the grip part slightly, but still it isn’t enough to unthread the grip. So the service and the advice is helpful and is working, but the pen itself is flawed.
I think I might just got unlucky and got the flawed one, because my friend in CA. ordered the same product(different color) and it doesn’t have any of the issue I encountered.