Before revision: If extra wires need to be used, or are used for principal reasons, they are typically routed entirely on the copper side of perfboards, because, as opposed to stripboards, nearby holes aren't connected, and the only hole in a pad is already occupied by a component's lead.
After revision: If extra wires need to be used, or are used for principle reasons, they are typically routed entirely on the copper side of perfboards, because, as opposed to stripboards, nearby holes aren't connected, and the only hole in a pad is already occupied by a component's lead.