One of many incarnations of the famous TDK D normal bias Type I audio cassette – in this case a 1995 version. This lightbox view of the tape takes advantage of the transparent casing to show both sides of the product, but more importantly, the innards. You get a good sense from this image of how simple compact cassettes really were/are. Other than the two reels and the length of tape travelling from one to the other, it’s just a set of guides, and a soft pad (bottom centre) which gently pushes the tape against the record and play heads in the tape machine.
If you look between the ‘spokes’ in the reels, you can even see where the ends of the magnetic tape have been pinched into the plastic to hold them in place. Quite a primitive system, but it’s remained essentially unchanged throughout the historical lifespan of the compact audio cassette. A tribute to a brilliant design which was pretty much right first time as a basic concept.