Which styling tool is most effective for creating volume at the roots?

A round brush is the ideal tool for creating volume at the roots due to its design and functionality. When used in conjunction with a blow dryer, a round brush allows stylists to lift the hair away from the scalp, permitting air to circulate and create lift. By rolling the brush at the roots while blow-drying, you can achieve a fuller look, as the bristles help to grip the hair, encouraging it to lift and bend at the roots. This technique is particularly effective for adding body and movement to hairstyles.

The other tools listed serve different purposes. A flat iron is primarily designed for straightening hair and would not create volume as effectively. A fine-toothed comb is typically used for precise styling or smoothing hair rather than adding volume. A straight razor is generally used for texturizing or cutting hair rather than styling it for volume. Thus, the round brush is specifically suited for achieving voluminous styles.