This pen is Platinum’s second run at making a response to the Pilot Capless, the first being the Knock… which was smothered to death in the mid-1960s under patent lawsuits brought by Pilot. “Knock” was descriptive of the mechanism; it is, as I understand it, a generic term in Japan for just about any button-activated writing instrument. The word figures into Platinum’s descriptions of the Curidas, too, with references to the progenitor pen, the mechanism, and hinted at in the model number: PKN-7000
Unlike the Knock, the trapdoor mechanism of the Curidas doesn’t offend Pilot’s patents. The extremely long throw of the button is needed to run an inner “cap” forward to the point that an little actuating toggle on the door can drop into a bulge on the outer shell. Once this engages, the point-carrying core continues to ride forward until the mechanism reaches its locking point. That same toggle shoves the trapdoor back into place, which is not only an elegantly simple design but avoids the tiny little spring that holds the door on the Pilot. I do have some concerns about the longevity of the hinge on the trapdoor, as it appears to rely on the flexibility of the relatively soft plastic of the cap.
In the promotional materials, Platinum mentions for some reason how far out the point extends in its deployed state, without any direct reference to a particular Pilot model whose point doesn’t protrude very far, making it easier to see what is being written. I can’t say that I’ve had a lot of trouble with any given model of retractable fountain pen on this point, but it’s a nice gesture.
I’m not inclined to take my Curidas apart, but given the number of moving parts I would not be surprised if this model can wrest the “World’s Most Complex Fountain Pen Mechanism” from the Sheaffer Snorkel. The inner cap has a spring of its own which would hold it forward without the main retracting spring being compressed. To refill the pen, one merely has to unscrew the barrel, then disengage a bayonet-style lug that keeps the core attached to the cap unit, then undo a similar fixture to remove a shroud from the cartridge (or the converter). Snorkel’s complexity grew in pursuit of easy filling, while Curidas in chasing one-handed cap-removal has made refilling a major undertaking.
In apparent response to a complaint about the clip on the Pilot Capless, Platinum has made the clip on the Curidas removable. It’s not easily removeable, but the necessary tool is provided. While this is a nice gesture to those who find the clip interfering with their use of the pen, I’m not sure it completely undoes the stated problem. With the clip gone, there remains a small alignment fin. I think this also helps to prevent the clip from rotating, so the fact that it looks very likely to break off without the protection of the clip is a worry. If one is indeed vexed by the clip, this little protrusion is also likely rub them wrong too.
The writing properties of the Curidas are very pleasant. Some might find the barrel a little too thick for comfort, but it sits nicely in the hand, and the point is extremely smooth– I find it rather better than the noisy gold points found on their more expensive models.
Production Run: Released in early 2020.
Cost When New: ¥7700 (according to the company website).
Size: 15.3 cm long retracted, 14.0 cm deployed.
Filler: Proprietary cartridge, capacity approx. 1.2 ml; will accept Platinum’s converter as well, capacity approx. 0.5ml.
If you are relying on the preceding information to win a bet or impress a teacher, you should read the site’s scholarly caveat. Remember, this is the internet, and it’s full of bad information.