Four dry cleaners who handle leather goods offered the same advice: do not put leather goods in a vacuum bag, ever. You will either deform the leather or risk mold and mildew.
Deformation
It is practically impossible to get the wrinkles out of leather. Leather often becomes permanently stretched, wrinkled or otherwise damaged in a vacuum bag.
Moisture
Vacuum bags fail frequently, allowing in the moisture that they are supposed to prevent. Mold and mildew may sometimes be removed from cloth with ammonia, but it rots leather and cannot be effectively removed.
Cloth Garment Bags
As an alternative to vacuum bags or even plastic garment bags, dry-cleaning professionals recommend cloth garment bags and hanging the garments in a cool, dry place off-season.
Hanging
One dry-cleaning expert says that fur coats are always hung to retain their shape or sometimes loosely boxed. He advises treating leather garments the same way.
Some Uses
Vacuum bags may be useful for stiffer items like purses and shoes on a short trip, but should not be used for longer storage.