Rubber

Sticky Resin can be converted into Rubber using any furnace or Extractor. The Extractor is the most efficient method, but it requires a source of electricity, making a furnace your only choice when first starting out. Rubber Wood and saplings can also be converted into Rubber using an Extractor, but they yield significantly less Resin. Rubber is primarily used in the creation of Cable.

Usage
Rubber can be used to insulate many types of wire, most notably Copper Cable. As such, rubber is used in the crafting of many other recipes, such as Batteries, and therefore Generators and Bat Boxes, as well as many others. There is also a secret use for rubber, think about its precursor and it might come to you. ..