Full Hairs

Investigating the claim ‘Full Hair’

Iryna Kruse presents on the HairS 2019

The desire for full hair is – especially for women – a globally pronounced need. In this respect, there are a variety of products whose application should result in ‘fuller hair’. Iryna Kruse will be addressing this topic at ‘Hairs19’ with her talk ‘How to assess the appearance of full hair’. She will present background information and possible biophysical measurement methods. The ‘Hairs’ is a scientific hair congress, which is organized annually. This year, the congress will be held in the Black Forest, Germany, from 11 to 13 September.


Hair is the crown you never take off. Strong, thick and voluminous hair is a main ideal of beauty. However, due to hormonal shifts, stress and the rising pollution hair loss and thinning have become a more common issue. Therefore, products are designed to make hair appear less thin and flat to receive an effect of strong voluminous and fuller looking hair styles, having tension and feeling vital.
Biophysical assessments of hair volume on hair tresses enable objectively measured results on how products like hair shampoos, conditioners, hair styling products and other hair products perform with regards to “volume-increasing”, “long-term styling” or “not-weighing-down” efficacies.
Our aim was to develop a method that is suitable to evaluate the volume-increasing and strengthening efficacy of hair care and styling products that are claimed to make the hair look more.
On the one hand, the well-established method for investigation of hair volume of human hair tresses by is especially designed to determine volume-increasing effects of hair care products. The area of a shadow thrown by a round-bundled hair tress is determined in an angle range of 0° to 180° by image analysis. Since the hair tress is symmetric in rotation, the mean area value is proportional to the volume of systematically increasing numbers of hair fibers. In a further step, the results are compared with benchmark values of untreated tresses of different tress volumes due to different amount of hair. Therefore, the resulting volume assessed is related to the look of different tress weights. Claims like “looks like more hair” can successfully be substantiated with this method.
The same concept was then adapted to the evaluations of hair bending force to evaluate the strengthening effect of hair care products on powerless, flat hair.
Tresses with high hair amount have higher bending force than thin haired tresses. This can be felt by shipping the swatches through the fingers. Styling products which increase the bending force of the hair can therefore mimic the “feel” of more hairs. In our method we match the bending force of a treated tress to untreated tresses with different bending force due to different hair amounts. Claims like “more tension” can be supported by this approach. Shampoo and conditioner products were investigated in this project to show the reproducibility and differentiation between the products.