 A bare aluminum disc can remain unchanged indefinitely if carefully stored, while the coating on a lacquer disc is subject to chemical deterioration, tending to shrink and become brittle due to the loss of unstable plasticizers, which can cause the lacquer to develop cracks, split off from the aluminum base disc, and in severe cases disintegrate into an unsalvageable rubble of tiny flakes.Most recordings on bare aluminum are believed to have perished in the scrap metal drives held during World War II.Aluminum was declared to be a critical war material and civilians in the US were urged to do their patriotic duty by finding and turning in anything made of it.