Final answer:
In a long round layer haircut, forward over-direction is used to create a seamless layer transition and maintain an even round shape with the lengths at the back becoming gradually longer.
Step-by-step explanation:
When cutting a long round layer haircut, the type of over-direction typically used is forward over-direction. This technique involves directing the hair forward towards the front of the head when cutting the layers. It is used to create softness and a seamless blend as the layers transition around the head. To achieve the desired round shape and maintain evenness throughout the haircut, forward over-direction allows the lengths in the back to gradually become longer as they blend into the lengths of the layers toward the face.