White wavy lines texture on a surface

Profile: Fine hair, lacking volume.

Definition: A term characterising flat hair, lacking in texture. The hair appears as if "stuck" to the roots. It is more fragile and gets damaged more quickly.
Internal and external causes: Genetics; hair ageing; long hair (gravity); use of unsuitable hair products; accumulation of sebum or dirt on the scalp (weighing down); humidity; repeated highlights or colouring; use of high temperatures from hairdryers or straighteners.
How to reduce or eliminate: Invest in a densifying shampoo rich in keratin, plant proteins, amino acids, and biotin to add body to the hair, while stimulating growth at the root; opt for a short cut to add lightness; apply a styling mousse to structure the hairstyle and add volume; rely on a dry shampoo; dry the hair upside down to create volume; choose curls/waves for a voluminous impression; use a hair diffuser to separate strands and create texture.
Preventative steps to take: Use a hairdryer at a low temperature; it is better to avoid long hair which tends to accentuate the effect; use hair products without silicone.