Room separator that shows up in the editor but not 2d pdf

[f0d]

Hey all very new user here
I'm trying to find a way to add a room separator between rooms that is visible in the editor but comes out invisible in the 2d pdf that is generated
For example inbetween dining room and kitchen or dining room and living room
Any help would be greatly appreciated
Thank you

[Puybaret]

Maybe adding a thin box could help if it's used to hide room borders or walls, but except the light selection rectangle which appears around each piece of furniture only at screen, everything in the plan will be printed the same.