Ask HN: Are there examples of 3D printing data onto physical surfaces? | Hacker News Reader

Ask HN: Are there examples of 3D printing data onto physical surfaces?

40 pointscatapart78 comments

I had a thought about encoding a very small amount of data onto some kind of "disk" using 3D printing as the mechanism for filament-based storage. The assumption was that using common 3D printer measurement tools (like for bed-leveling) would provide a way to read back whatever data was encoded onto the surface.

Since that seems like a pretty well-known concept, crudely applied to a domain I haven't seen it in before - but is already large and growing fast - I'm assuming that others have thought of this? I was hoping maybe someone had implemented something like it? And then, obviously, if that proof of concept exists, I'd wonder about some kind of advanced version that used specialized equipment for the reading (and possibly the writing/printing).

In any case, I'm just curious. I was thinking about long term (century +) archival storage, or encryption keys only stored as the print with no digital copies. Stuff that wouldn't need tons of storage, but would be crucial to maintain statically. It probably wouldn't be useful for that, which is why I assume I'm not finding much in my searches for it. But I was just wondering if anyone knew about it, in case there is stuff it's good for.

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How much data do you want to preserve?

I know it sounds “boring” but it is hard to beat a good acid-free archival paper printed with a good quality ink. Stored in the right circumstances (not too humid, dark place, not on fire) it should last half a millennia easily. It is also pretty much guaranteed that whatever happens we will have the technology to read it again.

Exotics like laser engraved metal plates or ceramics might be better if you have a lot of data and can’t guarantee your storage will be fire and flood free. If you don’t have a lot of data you can also think of engraving it into stone or press it into a clay tablet and fire it. These mediums are known to be very stable even in adverse circumstances.

Right on. Simple text/encoded strings weren't really on my mind while imagining the more complicated solution, but you're right that data is probably best preserved with just "printing" rather than 3d printing.

I didn't have an amount in mind, I was just kind of wondering about the hobbyist aspect. Like if I woke up one day and realized I need to archive something and my most readily available tool was a 3d printer, would I have to come up with my own scheme, or has someone already done it?

https://news.ycombinator.com/item?id=30820836

OPTAR: 2016

https://ronja.twibright.com/optar/

That reminds me a lot of a QR code, but extended. At which point, I have to ask: Why not just use QR codes? They have the advantage of being ubiquitous, although I'm very open to the idea that they have disadvantages or leave improvements on the table.

The main advantage is information density. QR codes dedicate a lot of real estate to error correction, but the protocol is really optimized for a few words, not kilobytes at a time.

It's also a problem if you need to segment your datastream onto multiple pages You've got to define a protocol for your stack of QR codes with that new encoding

If you do not have a lot of data, carving it in stone and hiding it in some desert might give the best results.

Embed it in the DNA of a cockroach.

Not a good idea. Since the DNA has no use for the organism, you work against evolutionary pressure and energetic efficiency.

Pro-tip: use sections of mitochondrial junk DNA.

OK. Junk is not important. Why should it be stable? What is the driving force against random mutations?

How about b/w laser printers? Since black toner is made of carbon black and plastic, I imagine it has an extremely long lifespan.

Beware flaking toner. I don't know if it flakes due to age or only immediately after printing.

https://duckduckgo.com/?q=laser+printer+flaking

I do not know. But the best evidence of something surviving for 500 years is looking at things which have survived that long already. Laser printers were first invented in the 70s. So the oldest surviving laser printed pages are like 50 years old. You can of course do things like accelerated aging tests, or reasoning from chemical composition, which can give you ideas. But to be certain it is better to be conservative. With inks we have more experience. We have plenty of 500 years old books and through the years we learned better what survives and what causes problems. Now of course that doesn’t mean that every ink will be better. Just that there is a better chance that the best inks, specifically formulated for longevity will perform better than the best laser prints.

That plus inks penetrate into the paper while laser prints are baked onto the fibers. Which i feel is better for staying there long term.

But who knows. Maybe there will be an archivist in 2100 on the moon cursing my name for suggesting inks instead of laser prints. Maybe by then it will be clear that properly formulated tonner is actually better. In some sense only time will tell.

First example I thought of is the titanium punch sheets and wordlists for crypto wallet recovery phrases https://shop.ledger.com/products/cryptotag-zeus and https://github.com/bitcoin/bips/blob/master/bip-0039/bip-003...

There is also Microsoft Project Silica which I recall seeing in person at their EBC playing back a movie from it https://www.microsoft.com/en-us/research/project/project-sil...

Then there is m-disc which uses the DVD+R and BD-R/BDXL standards but writing to a sort of glass rather than to the traditional medium. These are cool as they play back n regular players too. https://www.mdisc.com/

Unfortunately, currently produced mdisks are not the same as older ones. Requirements for media has been relaxed a while ago, most disks are not meant to last 1000 years anymore. Still, I don't know any viable alternative, besides maybe LTOs if you're lucky to know somebody with reasonable drive (not sure about US, in EU drives are quite expensive, and I mean used drives of course).

Edit: found Reddit discussion I learned that from: https://www.reddit.com/r/DataHoarder/comments/13693k0/new_de...

I run a business that makes 3d printed braille molds that are used to repeatably emboss paper. I haven't considered the molds being offline storage, but I suppose they are. I mostly operate with the assumption of a shelf life of 10 years for the PETG molds, but ink free, embossed paper has excellent lifespan if stored correctly.

I guess you could consider it an "offline datastore as a service." It would be a pretty good offline storage of keys with a way to request a paper copy. Certainly issues of trust and physical security but wrapping it with encryption would be easy. Also benefit from your government's legal protections for mail. There might actually be a usecase here.

Couple fast facts:

- Current 26 * 32 = 832 cells * 6 dot braille = 4992 bits/mold/page

- Possible 28 * 34 = 952 cells * 6 dot braille = 5712 bits/mold/page

- Maybe some more headroom, but that's what is possible with current spacings

Oh, very cool! Thanks for chiming in! Lots of good responses, but few that seem to have literal experience with the production. I appreciate the hard numbers. I think that was near the capacity I was assuming.

One or the more interesting things about asking this was seeing all of the types of "storage" that I hadn't even really considered. Braille didn't enter my mind, but of course it's a great analogy!

Seems like low data density. I recall some people talking about laser-engraving. IMHO engraving on a solid chemically-inert surface is more likely to be useful.

Like a CD/DVD?

That, or a data crystal.

The difference is, that one was (and still is) a widely established product and the other is in prototype stage since decades.

https://en.wikipedia.org/wiki/5D_optical_data_storage

Yeah, but standard DVDs and CDs degrade in less than the stated 100 years.

Yeah, that's why M-discs were created. Which only displaces the question to "will there still be drives to read them?"...

Yeah. I kind of lumped in engraving with 3D printing because the difference is really just a toolhead (simplified; motors, tolerances, etc, but still). But that's part of what the 'specialized tool' part of the question was meant to cover. Like, if you can store data in an additive way, you can obviously store it in a subtractive way. But... is anyone doing that with a 3D printer? Or a CNC machine, for that matter?

I think some of the other answered showed that people are, it's just pretty niche. Not something a hobbyist can (currently) do, but definitely the same idea at a production scale.

The benefit of a laser is that it can not only remove material, it can also discolor it. Either as a side effect of removing it or simply as a lower-power setting. And discolorations can be picked up with optical methods, which are far more accessible, reliable and higher density than 3d scanning.

Another variation of this is how we encode information into granite and other stones in Western funeral rites (grave stones): you engrave the information, then fill the groove with pigment. The pigment is susceptible to weathering, but the 3d information is pretty resistant. When the pigment is too worn down you just smear some more on there and wipe the excess away, leaving pigment only in the grooves, making the message clearly visible again

I’ve been plenty of graveyards where the old gravestones are completely unreadable. Did they use different/worse stone in the past or is this the most likely outcome of new gravestones after a couple hundred years? Several people have mentioned engraving into stone in this discussion but in this one example I can think of engraved stone, it doesn’t leave me feeling confident about the medium. What am I missing?

https://en.wikipedia.org/wiki/St_Mary%27s_Church,_Whitby

There are many headstones here that are completely destroyed by salty sea spray. Erosion of rock is something that is often told as a million-year process but it is very visible within your lifetime depending on the conditions

FWIW I think a more precise word for what you're looking for is "fabricating". Covers machining, lasers, printing, etc.

> But... is anyone doing that with a 3D printer? Or a CNC machine, for that matter?

Do you count plaques on public landmarks?

> I think some of the other answered showed that people are, it's just pretty niche. Not something a hobbyist can (currently) do, but definitely the same idea at a production scale.

Definitely is doable, having done it myself. You can probably hit your century target using the more specialized FDM/SLA/DLP hobby feedstock, if you can guarantee climate-controlled storage. Millenia if you shell out high double to low triple digits for a print service with fancy industrial machines, or if you combine a home printer with ceramics or metal jewellery skills.

There are M-Disks. These are CD/DVD/BluRay disks which use a drive with a higher power laser and work by ablating a metal layer, rather than a photosensitive dye as in the lower-powered disks. Regular drives will read both kinds.

For a small amount of data (crypto keys?), consider deep laser engraving on stainless steel. That's very durable. Or even engrave text into stainless steel with a small CNC mill.

You can engrave QR codes, bar codes, etc. But there's a lot to be said for engraving plain text.

Just get a set of alpha numeric punches and blank dog tags for crypto keys. Much cheaper than engraving.

Good answer. A set of punches is about $25, and a manual dog tag stamping machine (set wheel to desired character, pull lever) is about $250. That will get you a tough piece of metal.

Related - this insane project to build the "most 3D printed" 3D printer [0]. The author has 3D printed mechanical components, motor windings, and a complicated electomechanical "motor controller".

The whole thing is intended to work from 3D printed punch cards.

I'm not sure how much of this project actually works, but it is interesting.

0 - https://clickprintchem.wordpress.com/2022/05/31/self-replica...

I'd probably also pick some kind of "punched" card; a print of some kind with holes in one place and not in another. The presence of a hole could be checked with a bed probe if everything was lined up correctly. I doubt the plastic would be intact for centuries like you want, but it would certainly outlast the printer you use to read it. A paper card would probably last longer though.

For high density, your best option is probably microfilm.

Wow that printer is fascinating!

Good point re. film, related to that see - https://archiveprogram.github.com/arctic-vault/

You can print QR code with different heights representing white or black. That piece of plastic would last a long time, and you could encode.....something. You could pint a version 40 (177x177) grid with a Prusa XL easily, and that would last for a few thousand years and be waterproof and fairly resilient to a lot of things. You could probably print a 177x177 grid on a regular Prusa MK4 and just have a color change layer. E.g. layer 1 white, and then layer 2 black. This would be 2,953 bytes.

You could even get a binder, and then print the QR codes sheets as 'pages'. You could print these thin enough to do 1mm sheets. That means ~ 120 of these in a 5 inch binder. So, a 3 ring binder of 1mm sheets of 177x177 QR codes would hold about 346.2 KiB. You could store encryption keys in this way. You can probably push the density well past 177x177 even on a Mk4s pretty safely. I may try this later today.

I don't think that piece of plastic would last as long as you think. I think even ABS or PETG would be crumbling to powder in 100 years.

But you could use it as a stamp for thin sheet metal, that might last a longer time.

Or, press it into soft clay and then fire the clay.

Hey I just did a bit of a deep dive into this. Wow, thanks for pointing this out. It seems like 'PEEK' would last the longest, but most printers can't do this.

"Standard estimates for indoor PETG longevity are 10–20+ years under normal conditions, with some sources giving a more conservative 5–10 years. A century is 5–10x beyond those estimates under passive conditions." Wow! Thanks for pointing this out. This is fascinating.

Yeah it seems like a cheap CNC drill which can drill holes in steel sheets would be something that would last basically forever. Something like this:

TTC3018 CNC Router Machine 3-Axis Engraving Machine Metal Engraver GRBL Control with Built-in WiFi, 775 Spindle Motor, Engraver Desktop CNC for Wood, Acrylic, Plastic, Aluminum, PCB Milling & Carving https://www.amazon.com/TTC3018-Machine-Engraving-Engraver-Al...

Hey all! Wild to see my silly question pop up on the front page, but very cool! I hope it was because of a spike in interest for some reason, but...

Please forgive me, this is the first time I've ever been on the front page, but I'm seeing something odd? I posted this topic days ago and it was well received and then kind of done. But now it is showing both on the front page and on the ask page as having been posted only 8 hours ago. Is that normal?

I did see a topic the other day about HN being flooded with content, where some mods responded that they were doing work in that area. If I hadn't seen that, I probably would have just assumed that any ask that gets bumped up to the front page might get re-zeroed for posting time on all the existing comments. But given the other topic, I thought I'd pop back in and ask!

That aside, I do appreciate everyone's comments! I can't respond to them all, but hopefully I've hit all the main suggestions so far. Thanks again for the breadth of consideration!

Sometimes the PTB will give a post another chance at the front page when they feel it was a good post that deserved more attention that it got when originally submitted, and it behaves exactly like this - the time resets on the post and comments, and new discussion ensues.

More info: https://news.ycombinator.com/item?id=26998308

Awesome! TIL.

Thanks for the quick feedback! Makes sense, to me.

why not print onto paper and put it in a safety deposit box?

your X/Y resolution isnt going to be fantastic woth filament, but your Z is gonna really suck.

you could instead print(emboss?) like a barcode on some paper, and encase that in resin. the big benefit being that you can read it non-destructively. keep it out of the sun so whatever ink doesnt fade and you're set

Wouldn't that be just QR codes (and equivalents)? I suppose 3D printers can be used to etch/print them onto a durable material and then have it read back using the measuring tools you mention, but at that point I think you would be better off just 3D-printing out something like a a vinyl disc maker/reader and using that.

Modern chips made via EUV lithography can be thought of as 3d printed. Like the most mind bogglingly complicated 3d printing imaginable.

I dont think TSMC make ROM chips using their 5nm process but I think they _could_, if needed. So that would be a very compact way of storing info.

Nope. If you stretch the definition of 3d printed that much, then anything is 3d printed.

There is a lot of etching and masking going on in lithography, it is not localised additive manufacturing, the distinctive feature of 3d printed.

To satisfy the "disk" condition, would a vinyl record suit your needs?

I read somewhere about people using 3D printers to make vinyl records.

Wasn’t that an april fool joke ?

No. It was real.

How well it worked is a different story. I saw one of the records at Autodesk's Pier9 in their display [1]. But again...I never heard it play.

There was more posts at the time that went into more detail.

[1] https://flic.kr/p/Jb7naT

I think vinyl would, but as others have noted, it probably wouldn't satisfy the "3D printed" condition.

I know this wasn't in the original ask, but my focus was on what I would be able to do, as far as archival storage, if I had a 3D printer. The assumption being that it's easier for me to have, maintain, and use a 3D printer than it would be for me to have a vinyl press.

In the abstract, I don't see an obvious practical advantage of 3d steganography over 2d because the tools for 2d (printers and cameras) are more readily accessible and the processes of creation and reading are faster...particularly reading.

There might be corner cases where 3d makes sense...but it is hard to compete with decals/stickers, and 2d steganography can also use color and saturation as additional data dimensions.

But I could be wrong.

The advantage is much more durability. Hardier materials, and the print can lose an entire paper sheet's worth of mass/thickness, and still be readable.

Those properties sound beneficial in non-obvious corner cases.

In particular those when a sheet of paper’s thickness does not impact the required data density. While storing data on a wear surface is desirable and necessary to system design. And when conventional use of a engraved number as index to extended data is insufficient.

3D printing (additive manufacturing) usually involves layers that tend to be a weak point.

If you want something truly long lasting you might find substractive manufacturing techniques like CNC milling better. Indeed there are solutions from companies like Cryptotag for punching cryptographic seed data into plates / blocks of titanium. Something like this could be automated with a CNC router to store a bunch more data.

Titanium gets hype, but is it actually the best option considering chemical and fatigue properties? I find it implausible that tensile strength-to-weight would be the weakest part even for good old fashioned stainless steel.

A "vinyl" record is probably your cleanest option. Record players are pretty common so there's much less risk of losing the ability to turn it back into a digital file. (physical object to .wav file is commodity, .wav to you your original binary data is left as an exercise for the reader.)

3d printing filaments generally aren't very heat resistant, by the nature of the process. There are ways around that, like 3d printing metal or clay. But if we are allowed attachments to 3d printers I'd choose a laser or a pen, then use optical equipment for reading back the data

Best choice will be thick metal medium, such as stainless steel.

Probably use a 177x177 QR code with Q or H error correction engraved (deeply). I would probably compress the data and encode it as Hex so it can be stored in alphanumeric mode on the QR. You might need a series of QRs for larger data.

I completely hadn't considered the idea that QR codes could be made 3D (in fact, now I'm curious how much denser they can get, if you can both read and write them in 3D), but now that people have said it, it seems so obvious! I really like your follow up about using the error-correcting properties of it. A great feature that would be very unlikely to be realized in amateur 3d data implementation.

This was solved with M-DISC. The data is literally glassy carbon pits. http://www.microscopy-uk.org.uk/mag/artsep16/mol-mdisc-revie...

Right on. The only problem with M-DISC is that it's industrial only and most certainly not free for public use.

I know that isn't relevant to the question I asked, as stated, but the focus was on 3D printing because it is something any person could do, rather than something that has to be manufactured by specialized equipment.

Take a look at the ideas here https://www.monperrus.net/martin/store-data-paper

For long term data storage, you might consider using a UV laser to etch inside a crystal cube. This should last for thousands of years I would think. You could also read back the bits using optics which is non destructive.

Easiest way (I'm sure it's been done) would be to encode as QR codes and print that. (Multi-filament for two colours, or raise one of them enough for shadow or filament change.)

Some sort of wire recorder? The teeth of the 3d printer ‘driver’ (sorry lost on the terminology here) already make an imprint on the filament, maybe it could be made intentional

Wow! Now that's some outside the box thinking. That even seems to suggest that "watermarking" a print (or a small, hard to notice part of a print) would be possible.

I also think you could get denser storage that way? I guess depending upon how thick the "wire" is? But it's an interesting idea for both just printing the wire, and for the driver-teeth imprinting, separately. Very cool!

Not sure how it will survive extrusion. But yeah, the wire is a cylinder so you can ‘imprint’ multple ‘sides’. Another idea, some form of anti temper encryption like little particles (flock) inside the filament (like those colored rice anti temper methods)

You could print an old-school punch card, bring it full circle.

You could use letters for blind people with the amount of different letters you decide to use as base of a number system.

you could maybe do the inverse of what a vinyl does or something. the problem would likely be reading the data back efficiently for whatever it represents more than some encodingscheme to put data onto a surface (just looking at it from an encoding issue without problems of running out of surface so to say :p)

There are special companys, like for ex. Axnum, the make needle printers for steel.

Depending on how you define 3D printing: braille.

Do you want to build a time-capsule?

I've experimented with this using one of the commercial print-on-demand services. Not filament, a binder-jet sintering marine stainless steel type of process, IIRC. Slightly modified Noto Sans Extracondensed font with... Let me check the files... 0.1mm line width, 0.45mm lower-case "m" width, dense letter and line spacing, gets 3KB ASCII per square inch. ...Engrave, don't emboss, or the letters will come off with impact and corrosion!

Filling the engraved letters with black wax makes it optically legible under a good handheld magnifying glass. Then rub with vaseline/mineral oil/wax/ACF-50, mount on a brass holder (check relative galvanic corrosion order!), store pressed against aluminium or zinc sheet sacrificial anodes Just In Case(TM), inside polyamide or ABS case. Should last basically forever.

I designed it for manual reading, so the holder doubles as the "reader". Basically just a spindle going through a hole in the disk, holding a margin in the edge and center of the disk. The text is a spiral, so you can spin the disk to help keep the viewed region aligned under a higher-power microscope.

For home printing, probably the way to go is Formlabs wax resin (or equivalent), then either learn brass casting yourself or hire a jeweller to do it. Though you won't get as good resolution/density as the metal process I tried. And really, laser engraving'll probably be cheaper and better. Consider if good-quality paper and ink, maybe laminated, inside a Pelican case'll be more practical.

I wouldn't personally trust any of the common plastic printing materials to hold up for important data under oxygen, UV, fatigue, heat cycles. Are you sure the resin's not overcured or undercured, the filament fused correctly and won't delaminate, it won't reach the glass transition temperature during summer? And bacteria is already evolving to eat plastics. Maybe SLS/MJF polyamide's okay, but in that case, I'm not sure I'd trust the sintered structure for small details (and they don't have great resolution anyway).

> The assumption was that using common 3D printer measurement tools (like for bed-leveling) would provide a way to read back whatever data was encoded onto the surface.

> And then, obviously, if that proof of concept exists, I'd wonder about some kind of advanced version that used specialized equipment for the reading (and possibly the writing/printing).

At these small amounts of data, specialized read hardware just adds risk IMO. Plain text can be read manually or with OCR. QR codes can automate reading with a standard flatbed scanner or smartphone camera.

Consider ideas for encoding: Plain text, B64, hex, Reed-Solomon codes... 1-bit depth structure turns most of 3D printing's storage density into redundancy, but anything truly 3D adds read risk. If you insist on automating reading, QR codes will get you error correction, encode/decode software, and COTS hardware for "free". Personally I think human readability is a big advantage too. Maybe OCR text, and put error codes in a QR beside the text for byte-perfect computer input?

Compare: Memory of Mankind uses ceramic tablets in a desert cave. Arch Mission Foundation project uses holographic glass. Long Now Rosetta Disk engraves with electron beam on nickel, IIRC was/is also commercially available for personallized jewellery. M-Disc and Bluray (HTL?) have modern digital storage density, good stability, work with commodity hardware. ...See design considerations of prior art for digital storage in 2D, naïve 3D version is to just use these as a heightmap:

- https://github.com/cyphar/paperback - https://github.com/za3k/qr-backup/ - https://github.com/colindean/optar - https://github.com/Sjlver/psst - https://github.com/schroeding/paperstorage - https://github.com/intra2net/paperbackup

Also, don't sleep on the centuries of work done by archivists and historians! The top comment is right; acid-free archival paper has very good overall cost, density, stability.

You make great points! I appreciate the detail of the comment, and I don't particularly disagree with any of it. I think someone else mentioned gravestones that are etched and filled with black, so your suggestion of just doing that with sensible scales and fonts seems like a slam dunk, to me.

Bummer that it doesn't really seem feasible for a hobbyist, though. I take your meaning with the wax and such, but I think my solution would just be to go bigger and store less data. And I mean bigger like, 20 characters per print bed, or something. But then, at that scale, maybe a QR code would hold up well enough in plastic, too?

Overall, I think I've mostly learned that "archiving format" is a broad term that really needs to be collapsed by describing how the archive will be stored (and what extremes/complications to expect). In any case, thanks for the links and again for the detailed discussion!

> I take your meaning with the wax and such, but I think my solution would just be to go bigger and store less data. And I mean bigger like, 20 characters per print bed, or something. But then, at that scale, maybe a QR code would hold up well enough in plastic, too?

Only way to know is to try it! I think you might be surprised. QR codes (with high redundancy settings) are very resistant to corruption.

The idea with the wax is to transfer the data into a more durable final product... Lost wax casting, you print wax, cover the wax in plaster, melt the wax, pour a metal (or epoxy) into the plaster mold.

Disney has a patent on this

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