Before revision: It is easy to tell whether walls have scrim and sarking as their basis: knockiong on the wall will produce the sound of the wood, and any wallpaper laid over the top will have an uneven finish.
After revision: It is easy to tell whether walls have scrim and sarking as their basis: knocking on the wall will produce the sound of the wood, and any wallpaper laid over the top will have an uneven finish.