Dear Donia,
How do I properly store a sterling silver necklace?
Q. Dear Donia,
A. Dear Sean,
While archival tissue is fine if you can't afford anything else, it is not ideal as residual chemicals in paper, as well as plasticizers in plastics, can cause tarnishing of the silver rather than protecting from it. The best approach would be to use a silver-safe cloth such as Pacific Silvercloth. It is treated to reduce tarnishing. I have some at home for my silver objects and my sterling silverware and it works really well.
If the necklace is stored somewhere dry and in the silvercloth, you should be able to store it with the pewter as long as the pewter is not already starting to corrode.