Ensso Pen Uno Review

1 August 2016 By ian

Ensso Pen Uno review

The Ensso Pen Uno was the result of Kickstarter campaign back at the end of 2015. It was delivered on time and is now available on Kickstarter again, together with a pencil option. This is a review of the pen I received after pledging $25 in the original campaign.

Price: $30 through the current Kickstarter campaign; future retail price stated to be $45

Tip size options: 0.3mm, 0.4mm, 0.5mm

Barrel options: anodised aluminium in grey, silver, gold, and rose gold as standard; plus red and black (available in the Kickstarter campaign; possibly available as standard retail options)

Ink type: gel

Size: 13cm long, 0.5cm diameter (at the widest point)

Weight: 10g

Ensso Pen Uno retracted

The Pen Uno uses Pilot Coleto refills. These are readily available online and come in a vast array of colours and several tip sizes. The one drawback is that they have a small capacity and are relatively expensive for the amount of ink they contain. I’ve seen reports of problems with the finer tips in particular but the 0.4mm versions I use have never given me any problems. The colours are vibrant and the tips glide across the page.

Ensso Pen Uno undone

Refills are changed by removing a screw at the end of the barrel.

Ensso Pen Uno screw at end

Ensso describe the Pen Uno as the “Most Minimal Pen”. I’m not entirely sure what that means but it’s safe to say it’s a very slim pen. The aluminium barrel is just wide enough to encase the refill. It’s longer than it absolutely has to be (look at the length of that retaining screw) but this extra length makes the pen a little more comfortable in the hand.

Ensso Pen Uno in hand

At the business end of the pen there is a wider aluminium sleeve. It’s wide enough to be comfortable to hold. As the sleeve turns it moves up the barrel to reveal the tip. You have to be sure to turn the sleeve fully, in either direction, or it will move and rattle, and it does take quite a few turns to do this. However, once there, it stays put.

Ensso Pen Uno deployed

This is a neat idea that means the Pen Uno is about as small and light as it can be while still being useable. Perhaps that’s what “Most Minimal” means. It is in fact so light as to be a little disconcerting. There’s some part of the brain that makes you think that a small light pen ought to be a very cheap pen, which makes no sense but is something the Pen Uno has to fight against. This is a well made pen with a unique design that takes an interesting refill and it’s silly to put it down because it’s achieved its design goals. Would I feel it was worth more if it was a little heavier? Probably. Is that a sensible way to think? Absolutely not.

There are just two problems with this design. The number of turns it takes to fully retract or deploy, as mentioned above, and the fact that you’ve got crisp edges to both ends. This means the ends are easily chipped.

Ensso Pen Uno chipped end

The Pen Uno has grown on me as I’ve used it. It helps that I love Coleto refills but, as well as that, this is a pen that has managed to be incredibly light and slim while being completely functional.

The already funded current Kickstarter campaign ends on Wednesday 10th August 2016 so if you don’t want to wait for the retail pens to become available, you need to act quickly.


Uses the excellent Pilot Coleto refill

Very slim and light

Comfortable to hold and write with


Takes a lot of turns to retract or deploy

Finish easily damaged at each end