Tiny ziplock bags work great. They breathe energy if they breathe at all. Plastic doesn’t block morphogenic fields.
It doesn’t damage them physically either. It protects them well. When I used to keep them in my pocket without tiny zip bags to protect them, the clear coating of one would rest against the metal back of another. Over time this began to erode the clear coating.
With the ziplocks I’ve never had that problem again.