Help with papermill wanted

[LeFkY]

I know that maybe this is a stupid question but here goes:
Let's say my train takes wood to a paper mill, how can i not make the train take the paper from the paper mill this way loading my wagons and not beeing able to take wood

[spaceman-spiff]

Hi, at the paper mill, you have to give your train unload order for the wood and for the paper
This unloads the paper it loads !

[chevyrider]

For the lumber-train you get something like this:

Stop at the forrest.(station A) "Wait for full-load lumber".
Stop at the papermill. (station B) "Unload all paper".

This is enough. The train will unload the lumber and will not take back the paper to the forrest.