Mystery: Numbers written inside cartridges

[ethernautrix]

I bought this package of Mb Permanent Blue probably in 2014. Sticker says best before Nov15. I'm finally using them, just emptied one cartridge, and noticed...a message?

 

The number 45 written inside the cartridge. I examined the other cartridges (see photo).

 

The three on the left are unopened. All different numbers.

 

Can anyone explain why these numbers were written inside the cartridges? And what they mean?

 

[PAKMAN]

What a fun mystery!  Following to find out!

[ethernautrix]

Numbers also written inside Mb Mystery Black cartridges, Oct15.

 

Checking full cartridges (no loss from evaporation) of Mb Mystery Black, 2022-0011,  that I received today, and it's hard to tell, but seems there aren't numbers. Maybe the cartridges are too full?

[Mr.Rene]

Maybe ...a hidden message ...?  It is scary... 😲😬🤣

[dipper]

That is fascinating!

 

The numbers are clearly written by hand, not machine engraved.

 

The numbers cannot have been hand written onto the inside of the plastic tube after the cartridges had been formed on an injection molding machine.

Much more reasonably they could have been written onto the metal pegs or rods that are parts of the metal mold that define the internal shapes of the molded items.

 

As ink cartridges are hollow, and are not "blow formed" like some drinks bottles are, the mold must have some metal rods that each fill the spaces to be left open when the mold is opened up to reveal and eject the newly formed plastic cartridges.

Someone has hand engraved a number onto the outside of each of those rods, and that engraving has formed the letters we can now see in the texture of the plastic surface inside the cartridges.

 

What tool did they use to engrave the metal rods?

There does exist an electric metal engraving hand tool that has a vibrating tungsten pointed tip.  Makes a horrible noise, and a rather ugly series of little dimples on a metal surface when used to "write" onto metal. OK for writing on a pet's ID disc, but not suitable for engraving on a gold or silver sports trophy. (That sort of high-end engraving is done by highly skilled artisans using sharp chisel-like cutting / scribing tools.)

 

Zooming into the photo of the mysterious lettering reveals a series of little dots. The engraver used one of those electric vibrating tools.

 

Why do it?

One reason this is done in injection molds that are churning out tens of thousands of little widgets is quality control.

The metal mold parts can wear, distort, get damaged, and produce faulty plastic parts. If all the faulty cartridges are found to have "45" written inside then the factory knows that rod number 45 needs to be replaced.

 

Such numbers are usually machined into the mold parts, and are crisp and precise. I have never seen hand engraving used before this example.

 

I have four Duke 209 pens with injection molded plastic feeds. Each feed has one capital letter visible, very precisely formed by machine. I have an H, K, M, and amusingly what appears to be a mirror image N.

The makers of the metal mold parts remembered to mirror-reverse the mold to form the "K" correctly in the plastic part, but got confused by the "N" so it came out back to front in the plastic feed.

 

No such mirror effect worries in the cartridges. We are reading the numbers through the plastic, the same way round as someone with an engraving tool in hand saw the outside of the metal mold rods.

[InesF]

18 hours ago, ethernautrix said:

Can anyone explain why these numbers were written inside the cartridges? And what they mean?

The moment you find a "42" you know the answer. 😅 (and maybe you win a new pen ?) 😎

 

Jokes aside, I have only newer MB cartridges (around 2018-2020) with non-permanent ink and none of them has mystery numbers inside. So it must be a message from the past. I have no clue but I'm always curious - please allow me to take a seat here, popcorn and cold drink at arms reach ... 🧘‍♀️

[omarcenaro]

Well that is pretty intriguing. How odd.

 

Would have been very cool it they were Fibonacci series but they are not, so no secret messages to find the holy grail.

[ljz]

On 1/31/2023 at 10:23 AM, dipper said:

That is fascinating!

 

The numbers are clearly written by hand, not machine engraved.

 

The numbers cannot have been hand written onto the inside of the plastic tube after the cartridges had been formed on an injection molding machine.

Much more reasonably they could have been written onto the metal pegs or rods that are parts of the metal mold that define the internal shapes of the molded items.

 

As ink cartridges are hollow, and are not "blow formed" like some drinks bottles are, the mold must have some metal rods that each fill the spaces to be left open when the mold is opened up to reveal and eject the newly formed plastic cartridges.

Someone has hand engraved a number onto the outside of each of those rods, and that engraving has formed the letters we can now see in the texture of the plastic surface inside the cartridges.

 

What tool did they use to engrave the metal rods?

There does exist an electric metal engraving hand tool that has a vibrating tungsten pointed tip.  Makes a horrible noise, and a rather ugly series of little dimples on a metal surface when used to "write" onto metal. OK for writing on a pet's ID disc, but not suitable for engraving on a gold or silver sports trophy. (That sort of high-end engraving is done by highly skilled artisans using sharp chisel-like cutting / scribing tools.)

 

Zooming into the photo of the mysterious lettering reveals a series of little dots. The engraver used one of those electric vibrating tools.

 

Why do it?

One reason this is done in injection molds that are churning out tens of thousands of little widgets is quality control.

The metal mold parts can wear, distort, get damaged, and produce faulty plastic parts. If all the faulty cartridges are found to have "45" written inside then the factory knows that rod number 45 needs to be replaced.

 

Such numbers are usually machined into the mold parts, and are crisp and precise. I have never seen hand engraving used before this example.

 

I have four Duke 209 pens with injection molded plastic feeds. Each feed has one capital letter visible, very precisely formed by machine. I have an H, K, M, and amusingly what appears to be a mirror image N.

The makers of the metal mold parts remembered to mirror-reverse the mold to form the "K" correctly in the plastic part, but got confused by the "N" so it came out back to front in the plastic feed.

 

No such mirror effect worries in the cartridges. We are reading the numbers through the plastic, the same way round as someone with an engraving tool in hand saw the outside of the metal mold rods.

thanks for the very comprehensive and enlightening delineation

[ethernautrix]

On 1/31/2023 at 3:23 AM, dipper said:

That is fascinating!

 

Thanks for your very detailed response. Quality control might be one reason, but then why the different numbers?

 

Speaking of which, last night I took a photo of three Mystery Black cartridges (Oct 15):

 

 

30, 19, and 23.

 

Checking the other three cartridges... I have another 30 and 23! And, in use, a 43.

[ethernautrix]

On 1/31/2023 at 10:33 AM, InesF said:

The moment you find a "42" you know the answer. 😅 

 

 

On 1/31/2023 at 5:23 PM, omarcenaro said:

Would have been very cool it they were Fibonacci series but they are not, so no secret messages to find the holy grail.

 

 

Maybe I should play these numbers in some lottery. Ha. 

 

I was hoping a Montblanc aficionado would know the answer immediately.

[Lithium466]

I remember seing numbers like that in Reynolds cartridges (made in France) in the 90's, and possibly Waterman from the same era.

I examined some old Waterman long cartridges I have right now but didn't see numbers. Maybe too recent, or maybe I'm remembering that wrong and only the Reynolds had numbers. These were the two brands I was buying back in the days...

[dipper]

10 hours ago, ethernautrix said:

Quality control might be one reason, but then why the different numbers?

 

That is because some number of cartridges are formed all together inside the metal injection mold in one cycle.

(Like making ice cubes in the freezer - one freezer tray makes many ice cubes in one cycle. If one cell is damaged then the ice cubes from that one cell will be slightly wonky.)

 

Hunting with 10x loupe and a bright desk lamp, I found more numbers in, or on, my ink cartridges. What a surprise!

 

No marks to be found:

• Sailor (both 2016 production, and 2021 production with a different plastic type and revised labelling).
• Sheaffer Skrip (Slovenia).
• an unbranded Parker style.

 

Machine cut numbers:

• Pentel FP10 - On the back end sealing disc - usually inside & seen mirror reversed, just once seen on the outside.
• Platinum - On the outside of the tail end face.
• Waterman long international - Very faint, on the curved outside of the cartridge very close to the back end sealing disc.

 

Hand engraved or chiseled numbers:

• Manuscript short international - On the inner wall in the short area between nipple and shoulder.
• Unbranded long international - Inside, very close to the (black) end sealing disc.

 

 

[El Gordo]

Inky bingo

[Mercian]

Hmm…

 

…who is up for storing their old cartridges/noting down their mould numbers?

 

As @El Gordo suggests, we could play cartridge-mould Bingo… 😉

Edited February 3, 2023 by Mercian
Edited to remove answer already given by @dipper

[ethernautrix]

14 hours ago, dipper said:

That is because some number of cartridges are formed all together inside the metal injection mold in one cycle.

 

Thank you again, dipper. 
 

I've noticed "printing" (engraving or embossing or whatever the technical term is) (which might even have been used in your detailed answers, but I could have missed from fast reading) on ink cartridges. On these Mb cartridges, for example, Montblanc is clearly "stamped." Ditto Kaweco (which are the two cartridges I have handy at the moment). 

 

But "handwritten" numbers inside the cartridges -- that was tantalizing! I suppose an actual note would have been so much more fun. And more mysterious if in German, or weird in English, right?, since the cartridges are manufactured in Austria.

 

So, not much of a mystery after all. I'd just never noticed numbers (or anything) engraved on the inside of cartridges.

Just checked a cartridge from the recently-arrived pack... and it has a number. If there's a 42 in the bunch, I'll keep it, haha. (Use it first, right?)

[dipper]

First editions of rare books are the most sought after by collectors.

 

In ink cartridges, I do have one single number "2" cartridge, proving that some brands do start numbering at single digits.

 

But I have no number "1".

The hunt is on!

[Mercian]

On 2/3/2023 at 11:11 PM, dipper said:

But I have no number "1".

The hunt is on!

Beware!

A cunning manufacturer who is keen to sell More Cartridges might instruct the employee who marks the numbers of the cartridge moulds to commence the numbering at 2, just in case anyone is on a quest to find that elusive #1… 🧐