Home recording machines were made by a variety of companies, but the Wilcox-Gay Recordio machines were by far the most popular.

A low quality microphone fed the machine and the stylus would then 'cut' an acetate record. The record was actually aluminum based, covered with a thin layer of acetate usually in black, but other colours have been noted.

The quality of home recordings was usually quite inferior as the machines themselves had many sonic limitations.

Wilcox-Gay Recordio home recording machine
It wasn't after all, up to par with more professional equipment found in recording studios, but did offer home users the ability to hear themselves on record. Because the acetate was soft enough to 'etch', it scratched easily and wore fast. Turntable needles of that era were made of steel, tone arms were heavy, and degeneration of these records was relatively quick.

Found almost by accident, this recording by Hazel and Marjorie Dergousoff of Grand Forks, BC (Canada) well demonstrates the home-produced acetate record.

*This recording has not been denoised, declicked or remastered in any way, as to demonstrate the quality of these old discs.