Your printer is the weakest link here. Some of them apparently store printed files or can be hacked so you need to make sure that is safe or not connected to the net. This is why I don't trust paper wallets as an ideal cold storage option. Any file that has been created digitally and then also printed is gonna make me paranoid as to whether it is 100% safe.
Why don't you just write them down manually, or if you must print them out don't print the full passwords but clues to them or obfuscate them slightly? Depends how complex they are. Ie if your password for this account was password1989 just write p19 or something. Obviously don't use something as simple as that though. Also remember that if other people find your list they could use them as well.
Listen to this. I've written some down manually yes, but not in plain text either. I've got my own little algorithm which I use to make it look like a ordinary work document which wouldn't interest others at first glance. This is combined with other work documents so it gives it a little more camouflage.
Printing is a flaw in terms of security & that's why I've personally never dealt with a paper wallet unless written down manually myself. Honestly, It's much better to just write it down manually & make sure it's 100% correct with capitals etc. Although I must say the odds of someone 'intercepting' or looking at recently printed documents is very low.
Most of the time people will be safe, but if you want peace of mind, like I do, I imagine every way a person could get your coins. It seems sadly nothing is safe digitally if it's not encrypted well.
Trying to mask it as a ordinary document will be a good idea to further mask it, but if people are going to go this far to try get your coins they'll likely have a bot that looks for your keys. I'd be very scared of making a mistake righting them down by hand.
You could take a Polaroid picture of your private keys and then keep them hidden/safe. It's a good idea to make a note of your keys somehow just in case your wallet files ever become corrupted or lost.
Maybe you are just paranoid bro. I think it is ok to save those things in Microsoft excel.
It's not paranoia but being safe. People lose their coins daily to key loggers and viruses. Better to be safe than sorry.
