Here's why:

* Composition: Paper is primarily made of cellulose fibers, which are organic materials. Organic materials tend to be poor conductors of electricity.

* Lack of Free Electrons: Insulators have tightly bound electrons that don't move freely, preventing the flow of electrical current.

* Resistance: Paper offers high resistance to the flow of electricity, meaning it resists the passage of electrical current.

However, there are some exceptions:

* Moisture: If the paper is wet, it can become more conductive. Water contains dissolved ions that can carry electrical current.

* Certain Papers: Some types of paper, like those coated with conductive materials or containing metallic particles, could exhibit different conductivity properties.

Overall, a typical paper book in dry conditions is a good insulator.