The most reliable, inexpensive, and trouble‐free shielding method known at the present is spray coating using paints containing conductive metal particles. The best metals are those which do not lose conductivity due to oxidation. These consist of gold, platinum, palladium, iridium, silver and osmium. The least expensive is silver. A coating containing fine silver particles is an excellent conductor and shield. Paints containing fine silver particles have been available a long time but are very happy and very expensive. Their performance is, however, excellent.