Final answer:
In the clipper-over-comb hair cutting technique, the length is determined by the elevation of the comb and the angle at which the comb is held.
Step-by-step explanation:
When using the clipper-over-comb technique in hair cutting, the length of the hair is determined by the elevation of the comb and the angle at which the comb is held. This technique requires skillful coordination as the stylist uses the comb to lift the hair away from the head and then trims it with the clippers. The key to achieving the desired length and blend is how high or low the comb is lifted and the angle of the teeth of the comb in relation to the head.