Check out info on resin casting. You have a mold, mix the resin with a catalyst. Whatever is in the mold gets embedded in plastic. - This link doesn't include info, but it's a reminder to go check out more info on resin casting
10 Stunning Crown Molding Ideas: The Crowning Touch
Want to run new wiring in your house but balk at the thought of ripping out drywall? Let crown moulding come to the rescue. Hollow PVC crown moulding is an inexpensive way to hide cable, audio, and communication wires in any room.