Opus 88 Koloro Demonstrator Fountain Pen Review

Opus 88 Koloro Demonstrator
Fountain Pen Review

This is the first review by new contributor Dave Hassar. Dave is a product photographer by day, sci-fi, and fountain pen nerd by night. You can follow his Instagram account here for some excellent fountain pen, paper, food, and commercial photography shots. To read more reviews by Dave, click his author page next to the little pencil icon above!

Review Ink: Robert Oster Forest Green
Review Paper: Maruman Mnemosyne

  •  Description: An oversized demonstrator, filled as an eyedropper.
  • Nib: Steel Jowo #6 nib, available in Fine, Medium, and Broad
  • Filling Mechanism: Eyedropper with piston seal
  • Weight: 27g overall, 17g uncapped
  • Measurements: 5.75” (147mm) Overall, 5.375” (136mm) Uncapped
  • Color Options: Clear resin


Opus 88 is a brand that has been around for over 40 years, and has recently started making some first party products. The Koloro Demonstrator is one of their first offerings. It is oversize, offers a #6 steel nib and is made entirely of clear resin. Their eyedropper design is an interesting one which makes the possibility of a major spill much less likely. Let’s have a closer look at this entry from a new brand I am very excited to see more from.

Opus-88-Koloro-Demonstrator-036Appearance & Packaging:

Upon receiving your Koloro Demo you will be presented with a black faux leather box which has a magnetic flap on the front. Inside is a fitted foam insert that contains the pen as well as a glass eyedropper for filling the pen. I think it’s quite nicely appointed for the price point.

Opus-88-Koloro-Demonstrator-114The pen itself is a clear resin which has been turned into a straight cylinder with the slightest taper from the section back towards the rear knob. The end of both the body and the cap ends are flat and have been beautifully polished to be crystal clear. The Inside the ink chamber, you’ll find a frosted finish. The clip is matte black and has been folded into a ball at the end. It is relatively thin metal but has a nice spring and attaches securely. Branding on the pen is minimal, the only mentions of the brand are a printed logo on the cap and one etched on the nib. The steel Jowo #6 nib fits the overall proportions of this pen nicely. I do wish they had gone with a matte black nib to match the clip and nib to one another.

Opus-88-Koloro-Demonstrator-142Nib Performance & Filling System:

The nib is a standard Jowo #6 stainless steel nib. Mine is the fine and it writes smoothly and consistently. Being a #6 nib it is nice and big which matches the overall size of this pen. The flow is a nice medium wetness and with my heavier hand I can get some shading out of the ink on many papers. Opus 88 stuck with the standard Jowo curl design on the nib and etched their logo to add a bit of customization to it.

Opus-88-Koloro-Demonstrator-003All of the current offerings from Opus 88 are designed as eyedropper pens. The ink chamber has an o-ring to seal the section to the body and eliminates the need to apply silicone grease. There is also the piston which allows you to seal the ink chamber and prevent the ink from leaking. The knob at the back of the body controls this piston, and should be opened a few turns for longer writing to allow the flow of ink into the feed. When I first got it the rear piston knob squeaked quite a bit but it went away after a few cycles. Using the supplied eyedropper is quite easy as it has an angled spout which makes it possible to see exactly where you are pouring ink without having your hand in the way. As it is an oversized pen the ink capacity is enormous at nearly 3 mL. Cleaning the eyedropper is fairly straight forward, although there are quite a few internal threads that are a little tricky to access so you may have some ink get stuck. An ink or bulb syringe will really help you get to some of the tricky spots.


One of the main reasons I was intrigued by this pen was the fact that it is oversized. It is nearly the longest and definitely the girthiest pen in my collection. As such it fits my large hands wonderfully. The diameter of the section is quite comfortable and does not strain my hand. I find it especially comfortable during longer writing sessions. This is a pen that does not post although I think the balance would be much too far rearwards if it were to, so don’t really see this as a miss. Personally I find the weight is quite pleasant for the size as well, settling nicely into the hand.

Opus-88-Koloro-Demonstrator-192The section is polished resin with a slight hourglass shape in which the fingers settle perfectly. While smoothly threaded, the cap takes a full 4 turns to come off. I don’t know if it’s another safety mechanism to prevent spills but most of the time it’s just frustrating. Opus 88 have done a wonderful job with the finish on this model. All of the threads are snug but not sharp and there are no machining lines that I can see. Even the frosted finish in the ink chamber is completely uniform and the exterior is beautifully polished.


– Enormous ink capacity
– Jowo #6 nib provides additional flexibility for nib choice down the line
– Much safer for every day use than a normal eye dropper


– It takes 4 full turns to remove the cap, so don’t expect to take quick notes
– Lots of internal threads which can be tricky to clean.
– Large size will not fit all hands comfortably


The Koloro Demonstrator very quickly has become one of my 3 every day pens. I love the size and the fine nib. As one of the first new products from Opus 88 I am very much looking forward to what they continue to produce. The pen feels well made, has a beautiful, although simple, design, and writes wonderfully. At a price of $120 I think it is filling a hole, or at least an opening, in the market for an oversized pen that is not a premium or flagship price. While similar in terms of style and size, the Franklin Christoph Model 66 Stabilis starts at $170 and goes up from there depending on nib choice. For me the size and piston seal are two factors that have me grabbing the Opus 88 more often than the Franklin-Christoph.




2 thoughts on “Opus 88 Koloro Demonstrator Fountain Pen Review

  1. Very good review. This is off topic, but can you tell me the name of that cup and saucer? It has really caught my eye

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