Hi Lida.
These units are very useful for general storage:
They are known as Plan Chests in the UK. Flat Files in the US.
Most tend to be about A0 size, so will take full sheets of mountboard. For temporary storage of artwork prior to framing, I put a few sheets of spare mountboard in the drawers and then you can slip prints/paintings between the layers to keep them separated.
One thing you have to remember is: NEVER stand cups of coffee (or and other liquid) on the top.
The ideal for storing mouldings is to have a 3metre+ ceiling in a building with a constant temperature/humidity. The advantage of vertical storage is more a question of accessibility rather than the welfare of the moulding. Most framers (inc myself) have to store the longer lengths horizontaly. Usually on some sort of shelves or brackets. If on spaced brackets, it's best not to have them too far apart as the moulding can sag. The brackets also need padding.
In my experience, if a moulding is going to warp or twist, it will do so despite whatever conditions, good or bad, it's stored in.
Very damp atmospheres can cause any gesso on mouldings to soften and crumble. Any gessoed frames or mouldings standing on a concrete floor will suck up moisture and be ruined.
That's all the wisdom I can think of at the moment. Hope it is some help.
