Backcombing is a technique specifically designed to create volume at the roots of the hair. This method involves taking sections of hair and teasing it towards the scalp, which lifts the hair and creates a fuller appearance. The process helps to add texture and height to the hair, making it ideal for styles that require added volume, such as updos or hairstyles for special occasions.
In contrast, flat ironing straightens the hair and can make it appear sleeker, but it does not contribute to root volume. Blow drying, while it can add some volume depending on the technique used and the position of the blow dryer, is more about drying and styling the hair rather than the specific act of creating volume directly at the roots. Layering is a cutting technique that gives shape to the hair and can enhance movement and volume overall, but it does not specifically focus on root volume in the same way backcombing does.