It's all very well having a backup topo chart on paper but it has become effectively impractical to have paper backup approach charts etc. One might consider having paper printed out for the planned destination but much more than that starts to become a weight issue. When I last had a Jeppesen for Europe it just fitted into 6 volumes .... it's probably more now [this is a rant for another day] as well as many hours a month keeping the thing up to date. In practice all one can do is have an up to date panel GPS with approaches, an iPad and maybe a iPhone as last ditch backup.