Whether you collect Radko, Old World Christmas or vintage glass Christmas ornaments, you preserve their value if they emerge undamaged at each holiday season. To know how to store glass ornaments you need to know what damages them during storage. Number one is condensation and number two is rough handling.
Condensation occurs when the temperature and humidity fluctuate during storage. Water from the air condenses inside and outside the surface of the ornament and when it evaporates, it takes some of the finish with it. This causes the "age spots", interior flaking and exterior paint damage.
The spotting is caused by water settling on the lowest part of the stored ornament and then evaporating. If the lowest part of the ornament is the opening and cap, the possibility of age spotting is reduced. Store your ornament with cap down. Store your box of ornaments in the most temperature contolled portion of your home, where the temperature and humidity fluctuate the least. That is usually NOT your attic or basement. Control the humidity of your storage area. Use a dehumidifier if the humidity in your location is high. You can place packets of silica or coffee grounds in an envelope inside your storage box, but you need to periodically replace these and/or dry them in your oven at low heat.
The other source of damage is careless handling. Ornaments that can rub against each other can crack, break or damage each other's finish. Also take care that if you use metal hangers on your ornaments, that you remove these before storing. Many vintage ornaments are found with the hangers still attached and tell-tale scratches around the top surface from the hangers. Separate your ornaments from each other by using the original divided box for storage. [Collectors like ornaments in original boxes best anyway.] If this is not possible, invest in one of the acid-free storage boxes that are made for storing ornaments.
Acid Free Storage Box
Use acid free paper to cushion each ornament inside it's compartment. But be aware that if the paper gets wet, it will stick to the ornament and can cause damage when removed. Use sturdy boxes for storing your ornaments and don't pack too much in one box. Dropping an awkward box can easily result in breakage. There is some debate about the advisability of using bubble wrap as a storage medium. It is one of the best materials for cushioning, but some claim that the plastic will hold in moisture or leach chemicals causing damage.