I used to work in the mainframe print room for a large company. We had one of those 70's 'fishbowl' computer rooms with windows all around so the company could show off it's new hi-tech mainframe computer. People in neighboring offices who walked by the computer room daily were accustomed to seeing random stacks of paper packages on a table by the window.

I noticed that if you carefully opened the package, you could remove the paper, reclose the wrapper with a bit of tape and the package retained the shape and look of a full package.

I decided to start screwing with peoples heads and started stacking the empty paper packages in increasingly implausible arrangements. I'd start at the bottom with a full package for ballast and then put a bunch of empty packages on top that leaned impossibly to one side. The light, empty packages were discretely secured with a bit of invisible tape. I'd sit back at my workstation and discretely watch the confused double-takes that people would make.