How far apart do you have to keep pickups?

[beaubrummels]

Like the title says.

When storing spare pickups outside of guitars, how far apart do you need to keep them to avoid any magnetic influences of one against the other, degaussing issues, etc. ?

Likewise with pickup mags. How far apart do you need to keep them? Or what materials can you put between them that stop the magnetic influence of one to the other? (Is there such a thing?)

Thanks.