A trade

Woodsman

Creates various planks and scraps of wood for carpenters.

Where it works

Its bench

Each of these is a station an owner places on their land. What you can make depends on standing in front of one.

Mills logs into planks and scraps — one log doubles into two large planks, and keeps doubling all the way down.

16 of ours

The other eleven

A trade that cannot make its own inputs buys them, which is the whole economy in one sentence.