For Airway hand cutting:
Using A CARPENTER PENCIL OR BALL POINT PEN, draw a fine line with a firm hand to make a slight depression. Then drag the knife, with a new blade, lightly over the groove which further pronounces it. Pass a second time and add a little pressure. Now you have a workable slit.
Proceed with increasingly firm passes. If you go out of the slit then reverse direction so as to avoid repeating the error. After a couple of slices you will have it down pat.
