Which of these materials is typically not used in cable insulation?

Wood is typically not used in cable insulation due to its properties and the requirements for effective electrical insulation. Insulating materials need to be non-conductive, durable, and resistant to environmental factors like moisture and temperature changes. While thermoplastics, fiberglass, and taped insulation materials are designed for these purposes, wood does not meet the necessary electrical insulation standards. It can absorb moisture, degrade over time, and may develop conductivity, especially under humid conditions. Therefore, wood is not a suitable choice when considering materials for safe and effective cable insulation.