Simple oscillator, hypothetical PCB.

This was one of my earliest submitted layouts, and I had applied the logic of single-sided boards. And, because the preview of the boards on this Web-site happens to be faulty in the case of single-sided boards, I had gotten pessimistic, about whether the knowledge is still automatic with Professionals, that in this type of board, the conductive layer is always put opposite the component side. Therefore, my pessimism is completely lifted in that these single-sided boards were manufactured correctly, even though what I uploaded had failed to make the layer-choice completely unambiguous.