Tutorials Audio

Fritz Pfleumer: Iron Oxide on a Strip of Paper

By Infinite Creation · Profile

1881-1945

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At a Glance

Fritz Pfleumer (1881-1945) patented magnetic recording tape in 1928: iron oxide powder bonded to a strip of paper, later plastic. It replaced Poulsen's steel wire with something light, cheap, splicable and editable. AEG licensed the patent and built the Magnetophon around it, and every tape format down to the cassette and videotape descends from the idea.

Lived: 1881-1945, Germany, born in Austria
Anchor year: 1928, the magnetic tape patent
Strand: overlooked

Career

The problem as it stood

Magnetic recording had existed since Poulsen in 1898 and had gone nowhere. Steel wire and steel tape were heavy, expensive, prone to snapping, dangerous at speed and effectively impossible to edit: a broken wire had to be welded.

What he actually did

Pfleumer, who had worked on applying metallic coatings to paper for cigarette tips, applied the same thinking to recording: bond finely divided magnetic material to a flexible non-magnetic carrier. The magnetic medium becomes a thin coating rather than the substrate itself.

How it worked

Only the surface of a steel wire participates usefully in recording anyway, so the bulk of the metal is dead weight. A thin oxide coating on paper or plastic gives the same magnetic behaviour with almost none of the mass, and the carrier can be cut with scissors and joined with adhesive, which is what makes editing possible.

What it made possible

AEG's Magnetophon, and from there the entire tape era: broadcast recording, multitrack music production, the compact cassette, and videotape. Editability alone transformed radio production, because a programme could be assembled rather than performed.

What happened to him

He licensed the patent to AEG, which developed the machines while BASF developed the tape. His patent was later challenged in Germany on the grounds that coating a carrier was already known. He died in 1945.

Where the credit landed

Magnetic tape recording was developed in Germany: Fritz Pfleumer devised the coated tape in 1928, AEG and BASF built the Magnetophon around it through the 1930s, and Walter Weber established AC bias around 1940. Jack Mullin brought captured machines to America after the war. The persistent claim that Bing Crosby invented or funded the invention of tape is false: Crosby was an early and important adopter who backed Ampex, which is a different thing.

Known For

Only the surface of a wire records: the rest is dead weight.
Splicing with scissors and tape is what made editing possible.
"Bing Crosby invented tape" is false. He was an important adopter and backer.

Knowledge Base

What You'll Learn

The move from wire to coated tape is what made magnetic recording a production tool rather than a curiosity.

Why editability changed broadcasting

Before tape, a radio programme was either live or cut to disc, and a disc cannot be edited. Tape can be cut and rejoined, so a programme could be assembled from takes, mistakes removed, and items reordered. That changed what radio could be. From a performance to a constructed object. And the same change arrived in television only when videotape did in 1956.

Where This Fits

Pfleumer's tape gave sound a recording medium, one link in the chain covered in A History of Broadcast Technology.

FAQ

Q: Who invented magnetic tape?
A: Fritz Pfleumer patented coated magnetic tape in 1928, building on Valdemar Poulsen's 1898 magnetic wire recording. AEG and BASF developed it into the Magnetophon through the 1930s.

Q: Did Bing Crosby invent tape recording?
A: No. Crosby was an early adopter who used tape to pre-record his radio show and invested in Ampex, which was commercially significant but is not invention.

Sources

The magnetic tape patent was checked against the German record. Checked 20 August 2026.

German Patent DE 500,900, Lautschriftträger. Pfleumer's patent, filed 31 January 1928 and published 26 June 1930. It covers a sound carrier made by binding permanently magnetisable material in powder form onto a flexible substrate, which is the construction of magnetic tape.