This kind of driver's license holster contains documents. If you put the driver's license holster with documents in the filing cabinet, it will be moldy. It depends on whether the filing cabinet is damp or not. As long as the filing cabinet is not wet, the documents in the suitcase will not be moldy, but if the filing cabinet is wet, the documents will still be moldy in this suitcase because the suitcase is not sealed. If you don't want to be moldy, you will put it in a dry and humid place, or seal it with a sealable plastic bag.