Can I get some information on this one?
The seller had this listed as “ Yasutomo NIJI GRIP 500” but when I got it home I can see OHTO on the body.
I like the vanishing tip. Are there other models in this line? Hold old are these?
The clip reminds me of the GG1000, the way pressing it retracts the tip.
That’s a near-exact replica of my high school pencil, and one of the few pieces I don’t have. (I have an Ohto version, but I think my HS pencil featured Y&C branding. Also, I never understood why the barrel said “Ohto” until I re-discovered mechanical pencils in 2009.)
Ohto white-labeled this piece to (seemingly) everyone else, and now there are tons of up- and down-market variations of this pencil.
You could make a case that, for Americans at least, this is the most influential double-knock of all time.
I remember the excitement of learning about THIS version of double-knock mechanism when I’d only seen/used the more common Kotobuki design. Part of the interest was random comments from folks who had used the Y&C or NIJI in their drafting or architectural work. Finding out that Y&C = Yasutomo was the next ‘Aha!’.
Can I get some search term suggestions to help me locate some of these? I’m using “Niji grip” and get nothing.
I think the problem is that most sellers wouldn’t know enough to list them with specific terms beyond ‘double knock sharp’, i.e. ダブルノック シャープ.
Elton had a few of these for sale in 2021, and I scooped 'em up. Haven’t seen any since (not on YAJ or Mercari, either).
A couple months ago, I got super lucky with a random eBay seller who unloaded semi-transparent red and blue specimens, but that felt like a once-every-couple-years type of score.
In the “Japanese Translations” post in these forums, I included a search for double-knock (in kanji), and it’s somewhat effective.
But IMO, searches are for absolute amateurs. If you want to make sure you exhaust ALL possibilities, you must manually search through ALL new listings on YAJ and Mercari every day.
This is what I did for over 2 years; it was the only reliable way to find all the pieces I wanted at the best possible prices.
Seems to be pencil version of OHTO’s double knock ball point pen OB-500. I guess the pencil would be OP-500? Maybe searching for that can aid you. NIJI probably had some sort of distribution right.
I don’t have OHTO OB-500.
I understand double knock mechanical pencil but I don’t understand double knock ballpoint pen.
Does it mean knocking the top to write and press the clip to retract?
if this is the case, should the pencil be called triple knock?
Or it is a half press mechanism (like camera?)
Half press to write. Full press to retract? However, I see “PUSH” on ballpoint clip?
Yes, for the ballpoint it’s simpler… because there’s no movement as done for lead advance. Once extended, it’s locked in place. You full press the clip to release.
I think of all these wide-mouth double-knocks with textured rubber grip, the TOMBOW Protect is the most “handsome” of the lot. I do like how OHTO has a clear front section, though. It makes the retracted tip more visible.
Apparently Staedtler got into this line as well, but their version has been noted to be a bit inferior in quality.
I have the Platinum “W-Knock” cousin of this design as well (orange and green) which opted for a hard black grooved grip, rather than soft rubber.
The Platinum W-knock is, IMO, the best piece in this genre. It’s certainly the most heavy-duty thanks to the hard plastic grip and metal tip protector, but I like the colors, too (black, orange, blue, yellow, and green).
Have you managed to collect all color variants of the Platinum W-Knock? So far I’ve only gotten 2… and I’ve not seen them come up for auction much lately.
I have em all. I had never even seen all 5 color variants when a listing popped up in 2022 with 4 of them (2 of which I needed).
Nice going! Was it a buy-it-now, or did you manage to win the auction without too much bidding competition?
I picked up 2 of them so far, orange and green (and at pretty low prices, relatively speaking). I’ve never seen the all black one. But I’d love to get the yellow and blue eventually.
I re-traced my history on the Platinum W-knock series:
I hadn’t seen green or blue prior to seeing that listing, and I didn’t really care about the price because I wanted the entire set [paid $74 + $10 s/h + tax ($90.93 total)].
You keep great records, Chris! I ought to make a habit of doing this as well. It can sure come in handy for future pricing references, as well as knowing what was invested in case of future sales/trades.
Anyone here have the Sakura Writoll? Weird name choice for it. So close to “Rick Roll.” 
Of course, there’d been a glut of different variations on this theme, the wide-mouth plastic bodied double-knock made ubiquitous by OHTO’s Niji Grip (as noted at the top). It’s almost like every big maker got in on this at some point… although I think PILOT may have skipped making one. And they went about doing it with so many different colors and design choices. Some had front-end metal surrounds (collars/bezels) while others opted for opaque or clear/translucent ones. Some had plastic or rubber accordion rear plungers, while some opted for metal. Most had metal clips of various designs, but usually brushed wide flat designs.
I’ve got only 3 brands of this type–Platinum, TOMBOW, and OHTO (also Niji). I understand that there’s also models by Alvin, Tomato, Staedtler, and Yasutomo (Y&C, Penac). There was also Sunstar, made in China. Any other brands come to mind? I don’t think Pentel or Pilot have made any.
Anyway, the Sakura Writoll is still pretty easy to find. You can even buy them from eBay periodically, anywhere from $15~$30. I found one for stupid cheap from YAJ. Just lightly used, for ¥400 (silly price, since it’s cheaper than the proxy fee of ¥500–about $6.75 USD in total). I like the fact that Sakura put a metal bezel at the back end, surrounding the plunger. TOMBOW actually put just a chrome thin ring around the back edge of the PROTECT–it’s not a bezel. Platinum’s W-Knock not only doesn’t have one, there’s a step in the plastic there that makes it look like one was supposed to go there but was left off for some reason (or fell off later on!).
I think Platinum made the best example of this retractable double-knock plastic bodied wide-mouth pencil style. While the grip isn’t rubber (grooved hard plastic instead) the mechanism just feels a little more solid. Nice click-action. Front metal bezel-surround, which looks impressive when the metal mechanism tip is extended. The eraser has a lead-clearing tool attached to the retainer, and there’s a plastic disc on the back of the plunger showing the lead size–I think they’re the only brand that chose it for this style.
