What is composition of shellac base plate?

Answer 1

They contain Shellac as major component to which fillers and plasticizers are added.

Filllers like: Powdered Alumina and Mica which increases the strength. And Talc to improve the reproduction of fine detail of softened materials.

Platicizers include sterin and stearic acid. Stearic acid melts on above 69 degree C because of which shellac baseplates should not be overheated. If heated beyond 100 degree C they will start to polymerize which is a condensation reaction and gases starts to come out it ( seen as bubbling reaction).

Answer 2

The composition of shellac based plates is as follows: shellac, stearin, talcum. Shellac based plates also contain a chemical called mica.

Answer 3

Shellac base plates are most often composed of shellac, stearin/stearic acid, talcum, and mica.