OFFTOPIC
I absolutely disagree with his explanation and his recommendations. You can check the comments to see that he couldn't really prove his point in that video. Also, I think that you miss the entire point here. I'll stop at that as it's not the topic here...

No problem, that would be dumb. No one should straight split their seed, I agree.


The multisig is a solid approach, I cannot argue with that. Multisig is still more complicated than the simple approach I suggested. The scheme I suggested can be explained in a few sentences and solid, durable backups are easy to make. However, multisig needs a detailed tutorial and compatible wallets. It might be difficult to remember it all after a few years or if your family member would ever need to access your coins. 

Most importantly, the discussion started from just simply keeping the extra backups of your seed phrase, not making it totally hackerproof or other things if I recall correctly.

If you were to keep just 3 straight backups of your seed phrase in separate locations, you will be better off using the scheme I suggested. In the thing, I suggested If someone found one of your backups you will be safe from hacking for quite some time (at least a few months if not years), it will require some proper knowledge and resources (incl. time) to crack it. Furthermore, I haven't mentioned this idea as any sort of alternative to a multisig, as it's a whole different beast altogether, and I don't really follow why we are discussing it that way.


Probably, true. However, the approach I suggested is quite simple so probably no true need for a lot of explainers. As mentioned earlier multisig is still a more complicated thing.



Honestly, I haven't thought that someone might still make a wallet with 12 words nowadays, it's not a good practice. I mentioned 24th words seed in my example.
Cracking 4 words of BIP39 seed is hardly comparable to cracking 8 words. To crack 4 words you need around 2^40 combinations, for 8 words it's around 2^80, it's a completely different thing. ^{(not really precise math here though)} You will have 7 words to crack on one of the backups as the last word is a checksum, but it's not that much difference.
It will take quite a lot of knowledge and computing power +money  to crack 8 words and it still will take months if not years. Also they will need to get one of your backups in their hands first. 

And as we were discussing just a mere alternative for keeping your multiple backups straight in different locations, I think that's quite good for something that is so easy to do.
Even for 12th words (which is not ideal) it still beats keeping multiple backups straight and fully, as it requires proper knowledge to crack even 3 or 4 words. A bit harder to do than just putting the words into a wallet.

I am not arguing that one is better than the other, though. I'm not pushing anyone to use that scheme. Different things for different folks. Never meant it as an alternative to multisig. Just replying to your arguments.

It is a simple no-tech idea meant as a way for keeping multiple seed backups in separate physical locations, where you are not able to keep an eye on all of them for 24/7. 
This is quite a digression from the main topic and maybe it would be best to not make this the center of this thread and avoid jumping into this rabbit hole.

I didn't mean Shamir's Secret Sharing, it's probably too complicated for most of ppl including myself. Not a biggest fan of multisig, but it might be nice if you have a big holdings. I meant just very simple idea that you just split your seed into thirds. Then each copy has 2/3 of the full seed on itself. You just do it manually, low or no tech approach. For example 1st copy has words 1-16th, 2nd has 9-24th and 3rd has 1-8th + 17-24th. I think that it's simple and it works, it might be good enough for most long term hodlers.

About PO Boxes, we currently ship to post boxes that are freely accessed by third-party delivery companies like FedEx. This mostly includes mailboxes or virtual mailboxes that are operated by some 3rd party private companies. For the moment we might be unable to deliver to some post boxes that are operated by post operators like USPS in the USA, as they don't allow other operators to access them.  If you think this is something that might be desirable by some customers, I think we can look into adding international post/mail delivery, which should be able to reach regular post boxes. For most folks, it would be not an ideal option, but maybe for PO Box delivery, it would be beneficial.


Regarding the data. I am aware that data security is an important thing. We are not that big but we do take some measures to secure the data.
Currently, we offer everyone (not just EU-based customers) to ask for full erasure of their personal data and transaction details after the return period is over. A significant % of our customers ask us to do so right in the order form. This includes all data on our servers as well as all e-mail messages.
As an EU-based company, we are obliged to follow strict GPDR law, that requires us to delete all your data on your request. Also, it allows us to request the same on behalf of our customer to third parties like payment processors and delivery companies, which we do as well. We don't keep data at 3rd parties, just our servers and offline storage. Also we purge the database manually every few months, as I don't like the idea of hoarding the customers data indefinitely.
The only data that remains at us then are obligatory tax records i.e. receipts but we move them to offline and/or paper storage periodically which is kept in a separate physical location.
 
I am looking into making this process fully automatic which will allow us to, by default, delete everyone's data after 30 days from the delivery. It involves some work so it will take some time to implement, privacy policy needs some legal work too. We'll announce when it's ready. Probably then if someone opted in for a newsletter or sth we will just keep their e-mail address but nothing else.

^{Open to all suggestions for improving the data security.}


That's right. What I might recommend is to have your seed splitted in 2/3 way, which means you can read your seed while having any 2 out of 3 copies. Yet with only one of copies you cannot get the seed as it will require you to crack 8/24 of seed which still will take at best months if not few years. This requires having 3 safe locations, possibly different physical addresses. You should have them in a place where you can check each few months if it was untouched, for total peace of mind. ^{It's easy to do, but If you need details I can give you some instructions if you PM me. I'll probably make a tutorial at our site in the future too.}



Forgot to add previously that shipping to some remote or expensive locations is $19 instead of regular $9. Edited the original reply accordingly. This includes countries like Autralia, New Zealand, islands in the middle of the sea, Switzerland, Norway, some African and Asian countries. You can get the delivery price from the product page or checkout. Still it is free for orders everywhere over $100 like you just pointed out.

Please be aware that in some countries you can get charged by local customs office import tarriffs, tax or duties at delivery. We listed info about some most popular destinations at our site, but in other cases you should check how it looks like with your local customs office. Maybe that's what the OP, Agbe meant? I believe it could add up to $50 with $270 value in some cases.


Also it might be important to some folks here, especially in US market, that all prices at our site include all sales taxes so the prices = amount paid.

I oversimplified a bit when talking about a screw fit. We didn't make the holes larger or made the screws looser actually. The main difference is that sockets now are better aligned with threaded holes, so screws are easier to put in. In the past we had a bit of difficulty during manufacturing where sockets and threads (they are on different plates) were not that perfectly aligned as well as their angle was sometimes not perfect. I am talking about some minor things, that come from the fact that machining stainless steel is pretty hard, even using proper machines and tools. We just improved the process a bit.
So the previous situation was that it was sometimes a little bit hard to screw the bolts in (even at room temp). Now it is much smoother like it should be. However, the dimensional tolerances of the screws and threads are still the same and according to proper norms. The screws and threads offer the same durability, it even might be better now as it's easier for the user to completely tighten the bolts.  Hope I cleared things up.

You can read our comments on the tests in our blog post. The units that Jameson Lopp tested were shipped to him around half a year ago. Since then we improved the manufacturing a bit, so the screws are not as tightly fitted as before. It should mitigate some of those problems.

However, the important thing is that Coinplate will survive a house fire, even if it's abnormally hot. House fires burn at around 600°C/1100°F (at max can get up to 850°C/1500°F), and it survived a much higher temp of 1093°C / 2000°F in that test quite fine.


The most important thing for a backup is to survive and protect your seed phrase. If after a terrible disaster your only worry is to open your quite intact backup I think that's great.  Even if it may require using some extra force, a hammer or maybe a power tool in some worst cases.



My finger must have slipped, I meant 1.1kg. Yeah, that's how much our backups weigh. The weight of each is between 1.13-1.14 kg.
You don't have to just trust me, you can make the calculation yourself using for example this steel weight calculator. The dimensions for the whole unit are 10 x 105 x 138 mm. The material is 304 stainless steel which is stainless 300 series in this calculator. The calculator computes the weight as 1.15 kg or 2.53 lb, but there is some slight material loss during the processing (i.e. rounded corners, mounting holes, polishing). Screws fill their sockets almost entirely, though.



That's the same conclusion we have arrived at, after making some mockup designs. Glad that I helped and thanks for the interesting discussion.


Sorry for that dumb error on our site and inconsistency. As explained above, each Coinplate weighs between 1.13-1.14 kg. Thanks for pointing it out though, I'll review our site for errors.

Hello everyone, as a founder of Coinplate I would like to join this discussion and maybe try to clear some things out. There were some misunderstandings about our products. If you have any further questions, I'll do my best to answer them.
There is also my separate thread about Coinplate the seed phrase storage solution, if you would like to get more details and perspective.


Some of the photos that OP - Agbe posted are actually not of our product. Some of them are from other companies. You can check our products at our site getcoinplate.com. Sorry, but I cannot post photos yet.

m2017 correctly identified our products at our site:


Actually, our products start at $65 and international shipping is quite cheap. Wordwide FedEx shipping is $9 and we ship our products literally everywhere in the world.
Furthermore, You can get bundles that let you save a bit. For example, Coinplate Alpha costs $79, the 3 Pack is $189 (20% off) and 5 Pack is $276 (30% off). That's probably where this incorrect $300 price tag came from. And you get free worldwide shipping with orders over $100. €1 is now worth $1 at our site as that's how exchange rates look like right now.
 
To put the price of our products into perspective, some of the more known brands on the market are priced at $130 or more for a single backup and they don't offer that high durability in my opinion.

Coinplate is made using 2 thick stainless plates joined with solid screws that are set using threads in the plates, without a separate washer. Each Coinplate weighs 1.2kg / 2.5 pounds, so you are getting quite a heavy-duty unit. It is a stainless steel sandwich made from two plates each 5mm (3/16") thick.


Our products do not feature an extra, special space for 25th word (aka passphrase) and in all our communication we inform our customers that the passphrase should not be kept together with your seed phrase for security reasons. In every instruction manual in the box, we include some seed phrase safety tips, where we inform that a passphrase should be kept in a separate location and a backup should be made on a separate unit. Coinplate Punch has some additional spaces for memos and info, though. It is possible to make a backup of the passphrase on either Coinplate Alpha (if you use only letters of the same size) or Coinplate Punch (all symbols capable).



If anyone would rather make the backup themselves, go for it. I myself also like to DIY stuff in my house, but obviously not everything. People don't have to make themselves everything they use, there is room for both ready made stuff and DIY.

If you want something ready-made and super easy to use, you may just order something that's made like that - Coinplate Alpha, where you just press the center punch. No risk of smashed fingers. Also no other tools needed, as everything is included, so you can start right away. Anyone can do it on their office desk in just few minutes. It might be a bit more expensive than getting some thin plates from a hardware store or a set of washers, but remember that your time costs too and tools are not free either. Plus you get something of much higher quality and durability at the same time.

Also for Coinplate Punch we give an option of getting a bundle with an electric engraver, a bit more easy to use option than hammer +  stamps but it's up to you. We also ship bundles with stamps.



We did tinker with this idea actually. The thing is that when you screw the plates together, they are pretty tight themselves, so any corrosive agent has a hard time getting between the plates. Furthermore, even high-strength acids don't really affect the markings, even if the device is left open. The layout is deep engraved and the marks you make yourself are also pretty deep. You can see that it survived acid in Jameson Lopp's stress test. The gasket would itself be vulnerable either to fire, oil or acids (there are some specialized gasket materials but they are nowhere near the durability of stainless steel, we know as we make some industrial grade gasket ourselves).



Jameson Lopp have just recently stress tested our products, all of them received the top A A A rating.
Coinplate Alpha test, Coinplate Grid test, Coinplate Punch test and our blog post with a comment.



The logo on the front is just a sticker that can be easily removed if you like. After you do that, Coinplate looks basically just like a piece of scrap metal, and you can hide it pretty well if you think about it. The tamper stickers are obviously not mandatory, just an extra that's included in the box. Furthermore, the tamper stickers' material and color are almost the same as the metal itself so they blend quite nicely.


Hope I covered most of the topics mentioned here, if not, ask me anything you like.

Indeed, the unit he received was from the older batch, the screws used to fit pretty tight.
In the meantime, we made some improvements to the manufacturing process so the screws now have a slightly looser fit and are even better aligned for easier opening and closing. This should mitigate some of the problems.

However, I would like to emphasize that the most important job of the backup and screws is to protect the seed inside the unit, so it made a pretty good job, even if a bit hard to remove. After a house fire or collapse, I would be most interested in backup survival, even if I would need a hammer or power tools to open it.

Cheers!

Like on every market, there are multiple manufacturers because each of them has different ideas on how to achieve the given functionality. Some are focusing on low price, others on high volume production and some are offering sturdy, high-quality products like us.

What I wanted to achieve is to provide simple to use, ultra durable solution to the problem of storing your seed phrase for long time. We aim at durability that will hold your seed safe for 10,20, 30 or more years. If you would like to bury it in the ground, go for it, it will surivve. Would you like to put it inside a wall and forget? not a problem. Our backups are made from super thick plates and engravings are very deep. Also the design protects your seed inside the thick steel sandwich so it is protected from getting scratched or else.
 
In my opinion most of the devices on the market focus on being just durable enough while being cheap and easy to manufacture. It is not our case, we first thought about making it as durable as possible, not skimping on metal.
Our products weigh a lot, the stainless steel used is actually most of the cost. Other solutions use much less metal and are probably much cheaper to manufacture but 1 or 2 mm plates are not the same in terms of durability as our 2x5mm plates. Also, deep engraving takes a lot of machining time on proper high-power laser machines. You can check the last round of Jameson Lopp tests to see that other manufacturers often cheap out on this and just etch the markings on the surface so it is destroyed easily.

We went overboard with Coinplate design and made it excessively durable. Coinplate weighs over 2.5 lbs or 1 kg and is made with heavy-duty Stainless Steel. Both plates are 5mm or 3/16″ thick (gauge 6) and are joined together with stainless steel bolts to form a steel slab 10mm or 3/8” thick. This is much thicker than our competitors and we make it that way so you can sleep safe. Coinplates should survive getting run over by a truck as well as being shot with handguns. There is no reason to do that but that means it will survive massive drops or being crushed by a house rubble in case of disaster.

Hi there,
I've checked the article you mentioned and it seems that this applies mostly to regular, carbon steel that is zinc coated. My understanding of this "white rust" is that it eats up a zinc coating. Since Stainless Steel we use is "naked" and has no coating, because it is naturally rust-free, this will be no concern.

You can check the previous post where I linked up to a third-party stress test. It was submerged in 16% muriatic/hydrochloric acid and the product survived it well. Our own tests also show that it holds very well against corrosion. Getting into details, AISI304 steel can get some surface level,  minor rusting in sea salt environments after years of use but even there it will not make your seed unreadable. Everything is engraved quite deep and punch marks are also deep enough.

Furthermore, the design holds your seed inside a tight stainless steel sandwich which limits contact with any corrosive agent whatsoever. In the test I mentioned earlier, the acid was applied on an open device and even in that scenario, it survived well.

Hi there, it took some time but just a few days ago, Jameson Lopp posted the last round of tests and all our products were included.

We received a top, Triple A score for all our products.

You can check the test results for Coinplate Alpha here.
I upload photos from it below. It held strong, no data loss of any kind. You can check our blog post with commentary as well.

http://

Regarding the Coinplate Grid type, it depends on the user, some prefer the markings to be less obvious, hence the design. I myself prefer straight and simple solutions like in Coinplate Alpha.

Product update:
We changed the layout of our Coinplate Grid product to use a bit of encryption that some of our customers asked for.

You can check it out here on the product page: https://getcoinplate.com/product/coinplate-grid/

Basically, you punch the numbers of your seed phrase on BIP39 list instead of the words themselves.
Let's say that your word is "Plate", you check up the BIP39 Word list and see that Plate is number 1330. You use a center punch to mark 1330 on a grid. This way it is a bit less obvious when found. This is something that quite a few of our customers have asked and we gladly delivered!

The tiles-style backups are not as durable as I would like. They tend to be quite popular but I can't really recommend any. In our solution, the bolts are quite big and strong, and even if they broke, your data is still fine, just like you said. The thick plates where your seed is marked are not going anywhere, these are monolithic.


That's exactly what we recommend in our instruction manuals, unless you make more than 3 mistakes on each letter you should be fine. Still, we include a marker pen so you can test mark your seed first, double or triple check and after that make some dents in the metal.

Thanks for the replies and sorry for the delay. I must've missed my e-mail notifications... I'll reply to you all below.

Thanks for your interest. The product I offer is much easier to use than making your own with stamps and washers. If you pick Coinplate ALPHA or GRID You don't have to swing a hammer at stamps and risk injury. You can start right away after receiving the parcel and do your backup in few minutes, because you have everything you need in the box. Will ask Jameson Lopp to make a stress test of my products, hopefully, he would agree. The product is quite new on the market so probably not many people have heard about it before.

All products are made in Poland, European Union and are shipped from there as well.

Hello everyone!
I would like to share with you the project, that I’ve been working on for the past few months – the ultra-durable seed phrase backup – Coinplate.
I hope you would like it and could provide me with feedback about the products and offerings.

TLDR:
-   Coinplate is a new ultra-durable seed phrase backup
-   Seed phrase is protected inside by two 5 mm (3/16”) thick steel plates, bolted together
-   100% Stainless Steel (AISI 304)
-   Deep engraving
-   No permanent branding – easily removable logo sticker
-   Mounting holes so you can hide it anywhere
-   Two marking methods available:
        a. with an automatic center punch tool (center punch included);
        b. with stamps and hammer or electric engraver, stamps and engraver are also available;
-   BIP39 compatible, 24 words capacity;
-   Prices start at $65,
      value packs available;
-   If you like the idea, enjoy -20% discount code: BITCOINTALK
      I’ll also put some nice gift in the box for you guys.
-   Free worldwide shipping from 100$;

Website: https://getcoinplate.com/

product video: https://www.youtube.com/watch?v=5qGpz2UuG00

Cheers!

_______
Long version:

The story:
My family’s business is making nameplates and other metal products for heavy industry like mining equipment, wind farms, train engines etc. We have quite a bit of experience in making heavy-duty plates with durable markings that have to survive harsh conditions.

I’m also a cryptocurrency enthusiast and I’ve seen that the most popular seed phrase backups are quite flimsy and expensive at the same time. This is why I have thought about making something more durable, at the same price or cheaper. I also wanted to bundle everything you need in the box, so you could start right away with making your backup.

I’ve spent the past few months making the website and perfecting the manufacturing process. In the meantime, I got some customers that enjoyed the product so I expanded the delivery option from Europe to worldwide.  In the coming days I will also update the website with new photos and how-to videos. Wanted to spread the word a bit here, looking also for feedback and suggestions.

About the products:
All Coinplates are 100% made of Stainless Steel (1.4301 | AISI 304) which guarantees that they’re water and corrosion resistant. It is also fireproof up to temperature around 1.300°C/2.400°F, while house fires reach up to 850°C/1.500°F.  This grade of stainless is also corrosion and rust-resistant.  I’ll publish some stress tests videos in the coming days/weeks. My private stress tests show that it can take a lot of beating. I’ll try to ask Jameson Lopp to perform his own stress tests as well.

Coinplate backups are made of 2 ultra-thick stainless steel plates joined with stainless bolts. Each steel plate is 3/16" | 5mm thick, forming together a steel sandwich to protect your seed phrase. Bolts are also AISI 304 Stainless Steel and are 5mm | 3/16” in diameter. The layout and lettering are deep engraved in steel. This guarantees seed phrase visibility even after the worst accidents or disasters. 

Coinplate steel wallets are almost 3 pounds (2.8lb | 1.3kg), making them quite solid. All of this might be a bit too much for everyday situations, but I like to be sure that my seed phrase is secure, and I wanted for others to feel safe too.

There are 3 products available at the moment:

1.   Coinplate ALPHA - $79 – Easiest to use.  Two engraved steel plates with separate spacing for each letter. Marking with an automatic center punch.
Included in the box: Automatic center punch, marker pen, torx wrench, tamper-proof stickers, wood screws.

2.   Coinplate ALPHA - $69 – More affordable choice.  Two engraved steel plates with a table.  Marking with an automatic center punch.
Included in the box: Automatic center punch, marker pen, torx wrench, tamper-proof stickers, wood screws.

3.   Coinplate PUNCH - $65 – Punch your own seed. Two plates with engraved spacing for words. Mark your seed phrase with letter punch stamps and hammer or use electric engraver.
Included in the box: marker pen, torx wrench, tamper-proof stickers, marker pen, wood screws. Set of letter and number stamps available for extra $15, electric engraver available for extra $20. [/li][/list]

https://getcoinplate.com/

Three and five pieces value packs are available for ALPHA and GRID.

Everything is made in-house, so personalization is possible if you would like so.


If you have questions, feel free to ask here.
You can also take a look at FAQ section at my website: https://getcoinplate.com/en_US/i/FAQ/13, use a chat there or e-mail me.

If you read all of this – thank you! I would like to wish everyone here a great day.
I've been reading the forum for quite some time already, but never contributed in the past.
Cheers!