When you are designing panels, you can prevent some leading difficulties. If you have shapes that join at acute angles, you can alter the design to make the leading simpler.
Say you have two balls touching. You can design the panel so the cut lines intersect or touch each other. This makes for extremely acute angles in the cutting of the cames. Two balls touching in the presentation drawing will not look the same if leaded that way. So if you make the edges of the balls just a few millimetres separate, the cames will pass each other, just touching, and so have the appearance of the presentation drawing, rather than the appearance of overlapping.
You separate the lines by the thickness of the came you will be using for that area. If you are using 6mm came, the cut lines should be just less than that distance apart. This will allow the cames to go around each shape and the flanges of the came will just overlap. This makes for quick leading and a clean appearance.