>>11212653Plastic is actually worse for moisture than paper.
Since boxes are already made of cardboard, moisture gets in whether the inserts are plastic or paper. Since the plastic shells aren't air tight, moisture will get into the plastic clams and actually traps moisture in, since it can't get out as easily as it did coming in (vapor vs condensation).
Depending on the cardboard (whether it's waxed or laminated), cardboard inserts allow moisture to come out easier when it comes into the box.
But this is all rather moot. There's very little moisture coming into the boxes and you should control that by putting your cardboard boxes into airtight containers or using dehumidifiers. Moisture in itself does practically nothing to the toys and if there's enough moisture to cause mold, you seriously need to fix your house/room.
Also, plasticizers get trapped in plastic shells easier too. So it does more damage to your toys than cardboard does. The plastic shells also leak plasticizers and can damage your plastic toys.
In general, packaging isn't a pretty shit way to store your toys.
