Simple 2-piece sliding privacy shield / camera cover for your laptop. Glue it on.Print out the two pieces using layers no thicker than 100 microns. Place the sliding portion inside the track so that the little grippy slits are poking out through the slot -- that's the front. Use a piece of tape to keep it aligned while you carefully apply any suitable glue or tape to the perimeter of the larger piece. Apply it to the laptop and remove the tape and you are done. I tried using double-sided tape but it didn't seem to stick to the ABS I was using, so I ended up using hot glue, admittedly not ideal (and not that pretty). This sticks very well but be careful not to glue the two printed pieces together. Try to get glue all the way around, as any gaps can result in the sliding piece rotating and poking through there. This has to be extremely thin to still allow your laptop to close, which doesn't leave a lot of room for a good positively-gripping track. It could be improved by increasing the height of it so there's more area for contact. It could also be modified to look a little nicer and more polished, but I did this really quick.