How to create a physical/paper backup for bitcoin-core wallet? I am using bitcoin-core for my offline storage.
In electrum I can do a paper backup by writing down the mnemonics.
bitcoin-core seems to be using a different mechanism to generate the wallet.
What I am thinking now is that I can do a paper backup for each private key of the receiving addresses generated in the bitcoin-core wallet. So if I generated 100 addresses and transferred some BTC to all of them, I need to backup all the 100 addresses.
Is this the only way to do a paper backup for bitcoin-core wallet? If this is the only way. I think I should just generate 1-2 addresses only so it is easier to back up, and never forget to always put the change addresses back to those 1-2 addresses.
if I generated 100 addresses and transferred some BTC to all of them, I need to backup all the 100 addresses.

Bitcoin core is an HD wallet. So you should only need to backup the extended master private key shown at the top of dumpwallet.

# Wallet dump created by Bitcoin v0.21.0
# * Created on 2021-05-05T17:57:09Z
# * Best block at time of backup was 627544 (000000000000000000045a465b959072a715f47047141108ef14db64e2ee9049),
#   mined on 2020-04-25T08:34:02Z

# extended private masterkey:
xprv1x23XxXX456X7XXXXxxXx8Xxx9XxXxXxX01234X5xxX6XxX7xXxxXXXXxXxxXxx8X9Xx0XX1XxxX2XXx3x45xx6xxxXXXxxxxX7XXXxx8XX  


etc
Obviously you should practice recovery from this , and check the recovered balance, on a different computer, before relying on it. At least check that the generated subsidiary keys/addresses are the same.
It may be easier to recreate the wallet from an extended master private key (xprv) by using wallet software like Electrum, which has some support for this. Bitcoin core expects you to backup the wallet.data file rather than write down a number on paper.

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