Paper wallets — a private key printed on paper — were an early cold-storage technique, and we do not rank them because we do not recommend them. Generating one safely requires a trusted offline computer and printer; spending from one safely requires sweeping the entire balance at once; and a single sheet of paper is one flood, fire, or curious houseguest away from total loss. Everything a paper wallet did, a
hardware wallet with a steel seed backup does better — for about $80. If you are holding an old paper wallet today, sweep it into a hardware wallet using
Sparrow rather than importing the key.