Sticky Resin is a resource added by IC², and is the base form of Rubber.
Sticky Resin has no crafting recipe per se; it is acquired through the use of a Treetap. A Rubber Wood log will occasionally have an orange spot on one face (this regenerates if the tree itself is intact, at least the top leaf blocks), which can be right-clicked with the treetap to produce one or more resin. It's much easier to get resin if you have a larger number of rubber trees planted.
Sticky Resin will also sometimes (rarely) drop when rubber wood is chopped down.
Sticky Resin can either be smelted into a single rubber, or placed in an Extractor to yield 3.
With a NEW NEW NEW Treetap, you can now get perfect Resin!
Just stab it into a soft spot in the bark of a Rubber Tree and the sticky gold will flow!
You can use Sticky Resin for producing Rubber or even slowing people and animals down! HAYO!