To get a design from the studio all the way to the Steam Workshop.
1. Create or load a blueprint in the designer.
2. Finalize the blueprint and add it to the library.
3. Publish the library design to the exchange. This is done using a button on the exchange window.
4. Select the design in the exchange window.
5. Publish it to Steam Workshop. Blue button with rocket.
IMPORTANT
If your exchange entry was created before this update, the architect id is incorrect. You must republish those blueprints to the local exchange to fix them.
The architect id used to be your avatar id. That is meaningless to Steam. The architect id is now your Steam user id.
This was important enough that I edited the original post to mention it.
1. Create or load a blueprint in the designer.
2. Finalize the blueprint and add it to the library.
3. Publish the library design to the exchange. This is done using a button on the exchange window.
4. Select the design in the exchange window.
5. Publish it to Steam Workshop. Blue button with rocket.
IMPORTANT
If your exchange entry was created before this update, the architect id is incorrect. You must republish those blueprints to the local exchange to fix them.
The architect id used to be your avatar id. That is meaningless to Steam. The architect id is now your Steam user id.
This was important enough that I edited the original post to mention it.