Print bitcoin privat key for physical coin

[JanEmil]

I have a few physical coins.
Do it your self kits where you have to put the privat key below the hologram sticker.

Like this coin
https://bitcointalk.org/index.php?topic=2551453.0

I could print on small papir but can I read the key in some years if printed on paper. Maybe it is not even me own the coin when to use the bitcoin.

How do you print a privat key for long term durability?
It has to be so small it can be below the sticker 

[mithrim]

You need to be cautious as it's important to choose the right ink and paper, as choosing the wrong ones makes it more likely that the color fades over time or that it is more vulnerable to direct light. Have you considered laminating it?

[JanEmil]

Have you considered laminating it?

I am open for all ideas that works. Can you fold it small then?
Have you tried?

[mocacinno]

About the lenght of the private key (making sure your key can fit under a sticker), have you tought about using a private key in mini private key format?
https://en.bitcoin.it/wiki/Mini_private_key_format

As for your other problem (the durability), i guess it completely depends on your choice of materials. If you use high quality paper, good ink, laminate your wallet and store it in a safe (dry, no light, no changes in humidity) i guess it can last a long, long time...
You can also etch keys in metal, or wood,... I guess you're only limited by your imagination.

[JanEmil]

About the lenght of the private key (making sure your key can fit under a sticker), have you tought about using a private key in mini private key format?
https://en.bitcoin.it/wiki/Mini_private_key_format

Thank you. Think that is what I am looking for.

[jseverson]

You can save the secret key code with Notepad, Text Document, Excel, sau đó tải lên google drive hoặc qua tin nhắn của facebook. This is the way to save the key code in transparent multiple year.

This is actually a very bad idea because if your computer gets compromised, your private key could get stolen. If you only store them physically, they would have to be physically stolen. Store them digitally and you also run the risk of having them stolen remotely.