Storing In-Process Clay Projects

I have gotten several questions recently about keeping clay projects moist for longer periods of time. I've got ten minutes, so I'll give you a quick overview of what I do. I'm sure this isn't the only way to do it, but this method has worked for me for many years. 

Step 1 - Put clay projects onto a cafeteria tray with a layer of paper towels
underneath. I always label the tray with the teacher's name on a piece of tape.

Step 2 - Grab 4-6 paper towels per tray. Wet them,
 then squeeze them so they aren't too wet.

Step 3 - Drape the damp paper towels over the projects.

Step 4 - Place the whole tray in a plastic garbage bag.
(I get mine from our awesome custodian.) I then fold the open
end under the tray and label the bag with the teacher's name. 

Using this method, I can keep clay projects wet almost indefinitely. Just re-wet the paper towels a bit after each class. If there is a longer break in the middle of a project, I'll just squirt a little water into each bag to make up for any loss of moisture.