In the episode "Construction Junction" Dan and Roseanne are lying in bed and Dan is tossing and turning debating whether or not to join the prison construction project and you can see that he has pulled the blankets off him and the fitted sheet on the bed has come off the mattress at the bottom. So after he gets up and stumbles around and Roseanne wakes up and turns on the light you can see that the sheet is now on the bed as if it had just been made.