Can I make a trade route in which the resources are traded over an specific amount?
For example I want to sell ropes to the AI, but I want to always have a stash of 30 ropes in my warehouse in case I need to build a ship. Can I just export the ropes over 30? It's just too messy and tedious to micro the trade amounts all the time.
There is a screen for this, the wiki calls it the "Passive selling screen".
The interesting section from the article:
On the image I set the amount to 20 which means my Warehouse will only sell goods if there are more than 20 (I only sell those that are surplus).