This is where the option of having multiple copies of your keys stored in secured location comes in handy. With multiple copies printed in an offline printer or carefully written down if one gets destroyed the other copies replaces the lost one.

It will be preferable if it gets laminated as well to keep them safe from water or moisture attack. As already known never use online printer or any online backup option.  You can as well hide them in fire/waterproof safe. Lastly your duplicates should be kept at different secure locations.