Mikhail Proskurin - not quite right. More precisely, in fact-that is correct, but from experience, the morons dopechatnye not vkuril. Contour by cutting, in-the first, called respectively (the layer or group, if several circuits), and secondly do a contrasting color (depending on the layout, but all outlines needs to be the same color), and thirdly, the stroke should be thin, solid and center of the curve (and not inside or outside), in the fourth it is necessary to disable the visibility of these circuits otherwise morons dopechatnye print layout and outline together with the source clearly explains that the loop is in the hidden layer of such and such.