Dated back to Porcelain insulators history
Porcelain insulators date back to before the Civil War for telegraph wires. In North America glass was always the predominate material for communications insulators but porcelain has become the standard for power distribution due to its greater strength and surface resistance. Porcelain insulators shape has porcelain pin type insulator, porcelain line post insulator according to insulator application.

Porcelain insulators did receive the same level of interest as glass in the early years of insulator collecting, but have been gaining popularity in the last ten years. They are equally historically significant as their glass counterparts and available in as many colors and significantly more styles. Within the last 10 years or so a number of factors have contributed to the rapid increase in interest in porcelain:

More information has surfaced about the porcelain insulator business, such as porcelain pin insulator and a number of dedicated individuals have written books, articles, and reprinted catalogs that have significantly increased collector knowledge and interest in the porcelain side of the hobby.

More historical interest has been generated in the early development of power generation and distribution which has been primarily dependent on porcelain insulators. Distribution porcelain insulators include ceramic pin insulators, stay insulator and so on. Current linemen are much more familiar with porcelain, as very little glass remains in use today.

Relative Articles:
IEC BS 900mm creepage distance porcelain pin insulator
Composite polymer pin insulators medium voltage
Porcelain grey glazed pin insulator