Fabric is stored in two goodwill china cabinets with glass doors. They are definitely not air tight. I found a long piece of fabric, also in goodwill, that had been stored with mothballs. The smell was not too strong, so I bought it.
I cut it into 4 large pieces and draped the lengths over the inside of the top of the glass doors. That effectively blocks sunlight (DH leaves the garage door open and sun beats into the garage) and, so far, rodents. The smell has not leached into the fabrics at all.
the smell is fading from exposure, but I'm hoping the bugs have stronger noses than I do and will continue to avoid my fabric.
Maybe it's time to buy a few mothballs and re-expose the door cover fabric for awhile.