Cutting a shellac record, historically possible?

[mrd]

I'm researching records in numerous forms and I keep on coming across what I think is at worst an untruth, or more likely a poorly researched, or misunderstood presentation of historical recording techniques in that several sources describe someone undertaking experimental recording techniques using a shellac disc recorder in the 1940s.

My understanding of this is that it was never possible to record on to a shellac 'blank' successfully. '78s' obviously produced in the main by cutting wax masters (and poss later 'acetate') and in any case the date is post-development of instantaneous discs.

Anyone able to clarify that I might have the wrong end of the stick and it was in fact possible to do this?

[mossboss]

Nah man, You got it 100% right No way one can cut on what is commonly known as shellac discs/records, which is a misnomer really since the composition had a lot more ingredients than shellac which was a minor component, around 70 odd percent was fine ground slate, with a bit of rubber and some shellac, other additives as well, may be some urea? memory is getting taxed now, making up the balance, there is a recipe here somewhere I posted in a previous life
However, there was a pure shellac coating applied to a metal substrate that one could cut on, shellac as in its pure form the material excreted by certain bugs is generally used in french polishing plus specialty varnishes and other uses, the main problem was that the sputtering method used at the time so as to make the disc electrically conductive as was the practice with wax, was not suitable since under vacuum all the volatiles in the coating escaped ruining the metal deposit
Some experiments with silvering adopted from the printing industry as well as mirror making did take place but it was not adopted until such times as lacquer masters as we know them started appearing commercially, the method was based on an english patent around the early 30's, the industry is not known as innovative besides being very secretive of any methods used in the process
So you got right it in what is generally known as shellac records, which are far from shellac, hope the above throws some light for you, also in very early days cocoa butter was also used as a coating on zinc plated metal discs than etched in an acid to reveal the Hill and Dale cut so don't be surprised if you come across it, now that'll get you going, Ha
Best
C

[mrd]

Thanks so much. That's super helpful!

So there were discs that were pure shellac (on metal substrate) that could be cut directly! OK, this is possible then, though seems odd given the date (relatively late 40s) and the terminology as a shellac disc recorder also a bit odd.. Will do some more digging

Oh wow, didn't know that about cocoa butter!