save the page that generates before generates the add of the bitcoin or ltc, or ether paper add... then using an usb with antivirus to transport to a computer that never touched the internet, if possible, an apple...there you will generate offline the address, yep, the page that generates works offline...than u print on your print that never touched a wifi conection via usb...thats it hahahhahahha when u need to import the private key to a wallet, u go to the offline computer, write the key, transport to another computer offline yet, put the key, then you conect the wifi and import the key and the btcs...at this point that you imported the key to a wallet, I would not use the paper wallet u imported the private key anymore....better creat another one... hahaha at least I use on this way... :)