With the cello body finished, the neck heel is given its final shape and that shape, in its exact dimensions, is transferred to the body of the cello as shown in (18). The waste wood inside the mortise is cut out with a chisel, as shown in this ugly gash, (19). The fit of the neck is important simply to hold it in place and not fly out under string tension. Additionally, the aspects requiring exact fit are, the neck length [distance from the edge of the body to the bottom of nut, or the termination of the vibrating string length], straightness in the lengthwise direction, correct angle for the bridge height, as well as the correct overstand of the neck heel over the top. Though poorly illuminated, in (20), it is possible to see the gradual sliding back against the button extending up from the back.