I use that thechnique all the time to build RF assemblies where stray signals need to be bottled up to prevent unwanted signals in the wrong places. the advantage is not only is it a good shield but using scraps (cheap material) you can build custom enclosures for subassemblies. To keep this on topic at least somewhat. Years ago I built a PLL subsystem for a radio with a micro to do the tuning and display chores. The RFI from all that (8748 with led drivers and input controls) was unbearable. Boxed it all up as previously described using copper screen across the display opening and it was reduced to dead silent. Of course the few wires (power, slow parallel digital signal for tuning and switches) entering and leaving had to be properly filtered as well. Allison