Tape coated with powdered iron compounds was invented by the Dresden engineer Fritz Pfleumer in 1927. He used a paper strip, upon which hardened steel dust was set with varnish. This magnetic tape was far superior in acoustic quality to the previously used steel wire recorders. In 1928, Pfleumer built the first magnetic tape device with which the tapes could be played. In 1932, Pfleumer sold the rights to use his magnetic tape to AEG.