The article "Record Materials - Part II: The Evolution of the Talking Machine" by Warren Rex Isom gives the following formula for shellac (all of the descriptors on the right are his):
Shellac - 13. 6170% - a mixture of orange and garnet
Vinsol - 8.7234% - a low melting point molding modifier
Congo Gum - 0.9219 % - a somewhat flexible binder
While Filler - 37.4469% - powdered Indiana limestone
Red Filler - 37.4469% - powdered red Pennsylvania slate
Carbon Black - 1.3475% - colorant for appearance
Zinc Stearate - 0.4964% - lubricant for mold release
This article was published in a special issue of the Journal of the Audio Engineering Society, which they called the "Centennial Issue - The Phonograph and Sound Recording After One-Hundred Years", Vol. 25, No. 10 & 11, October/November 1977. Isom's article begins on p. 718, and the formula is given on the next page. For those who do not know his work, Isom became an engineer at RCA in 1944, and Chief Engineer of RCA Records from 1966 until his retirement 10 years later. He served as Guest Editor for this special issue of the AES Journal, and was also AES President during this period.
What surprises me about the formula is the precision of the percentages - to 4 decimal places! I have always assumed that Isom got this information from the RCA archives, but he doesn't give any references for this or his other 5 articles in this issue. I guess his tenure at RCA Records put him square in the middle of such "developments" as Dynagroove and Dynaflex (Dynawarp?). But, as Alton Brown says on Good Eats, that's another show.
This issue contains a wealth of good articles, by some very distinguished authors including Harry Olson, John Eargle, John Mullin, B. B. Bauer, William Bachmann, Robert Moog, and Thomas Stockham. (Part I of the article cited above is on "Chemical Technology in the Edison Recording Industry" by Leah S. Burt).
It's a free download for AES members, and $33.00 for non-members.
There's one used copy on Amazon:
From: Association for Recorded Sound Discussion List [mailto:[log in to unmask]] On Behalf Of George Brock-Nannestad
Sent: Wednesday, October 02, 2019 5:42 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] [EXTERNAL] [ARSCLIST] Book Review: "Sound Recording" by David L. Morton Jr.
From: Patent Tactics, George Brock-Nannestad
what a mess! It is high time that somebody knowledgeable after 13½ years finally looks inside the book. However, the fact that Stephanie Bonjack's article was published does cause reason for worry about the quality of the "peer review" of the ARSC Journal. They ought to have caught her sweeping statement about the respective diameters of LPs and 78s. But was the book reviewed in the ARSC Journal when it appeared?
If the book does not have a reference to H. Courtney Bryson, "The Gramophone Record", Ernest Benn Ltd., London 1935, then in my view it must be worthless as a secondary source.
I like your review: however, the reference to "pumice" is in itself misinformation. The mineral content of a shellac 78 rpm record is about 80 percent, however it is rottenstone, barytes or synthetic barytes, finely ground.
The Columbia laminated record did have finer grit for the surface layer on paper than the solid mass of the other 78s, and hence the background noise is closer to a hiss than the noise from solid records, which tends to have impulses superimposed.
I thought I had the book, but not yet opened. I do not, and I do not intend to pay for it.
With such a confusion, there is certainly room for a book that does it right.
> > -----Original Message-----
> > From: Association for Recorded Sound Discussion List [mailto:
> > [log in to unmask]] On Behalf Of Ron Roscoe
> > Sent: Wednesday, October 02, 2019 12:20 PM
> > To: [log in to unmask]
> > Subject: [EXTERNAL] [ARSCLIST] Book Review: "Sound Recording" by David L.
> > Morton Jr.
> > Folks;
> > I started reading Stephanie Bonjack's article "The Importance of LPs in a
> > Digital World" in the Fall 2018 ARSC Journal and when I got to the end of
> > the
> > second paragraph and read that "the LP with its larger diameter" [than
> > 78]
> > and also "the 78 which could only hold up to four minutes per side", I
> > wondered
> > where she got this incorrect information. The Endnote cited David L.
> > Morton's
> > book "Sound Recording, The Life Story of a Technology".
> > Folks, this book is full of errors! The 78 records were issued primarily
> > in
> > both 10" and 12" diameters, just like LP's are/were! LPs did not come
> in a
> > larger diameter. And, I believe the 12" 78 could hold 4.5 minutes per
> > side.
> > I have written a review of the first ~100 pages of this book on Amazon,
> > you can
> > read it here:
> > rv0_rv
> > <
> > The 9 major errors I found in the first 100 pages were enough to convince
> > me not
> > to read further.
> > It's really a shame that such a promising book is so full of incorrect
> > information. I hope the author can issue a second edition with more
> > attention
> > to these problems.
> > Sincerely,
> > Byron [Ron] Roscoe