EDD Sound Quality

[MisterGramophone]

Edison patented the use of stearin to preserve the surface of diamond discs, see attached. Its shortage was reported at the WWI period.
[/quote]

This was something I was aware, but not that it was patented. Possibly a thin waxy polish applied to the discs would have needed very little raw material per record compared with the varnish and powder blank.
[/quote]

So, diamond discs were just discs of china clay coated in resin coated in stearin?