 Engraving the groove into an easily cut and grainless lacquer, rather than indenting it into bare metal, made it possible to produce a broadcast-quality recording that preserved high-frequency detail and was nearly noiseless when new.As a result, professional recording services soon abandoned the use of bare aluminum blanks, although some amateur and novelty use persisted into the 1940s.From an archival perspective, the changeover traded long-term stability for superior sound quality.