Hair shine is an important indicator of hair health, product performance, and consumer satisfaction—particularly in formulations like conditioners, serums, and oils. To assess shine scientifically and reproducibly, two types of tests are typically performed: instrumental testing using a Glossymeter, and in-use testing with consumer panels or trained assessors.

Glossymeter Measurement (Instrumental Test)

The Glossymeter is a precision device used to quantify surface gloss by measuring the reflection of light on the hair surface. The test is conducted under controlled laboratory conditions to eliminate external variables such as lighting or humidity.

How it works:

• Clean or treated hair tresses (bundles of hair) are prepared and standardized in length and weight.

• A beam of light is projected at a specific angle onto the hair surface.

• The device measures the intensity of light reflected at the mirror angle.

• The result is expressed in Gloss Units (GU), with higher values indicating shinier hair.

Applications:

• Before and after treatment comparison (e.g. shampoo, conditioner, hair oil).

• Evaluation of long-term effects (e.g. after multiple washes).

• Benchmarking new formulations against market standards.

In-Use Shine Evaluation (Subjective Test)

An in-use test is often performed with a consumer panel or trained experts, who evaluate shine after using the product under normal conditions.

Procedure:

• Volunteers wash and treat their hair using a specified product for a set duration (often 1–4 weeks).

• Shine is assessed visually under standardized lighting, often by comparing with reference images or using a Likert scale (e.g. from “dull” to “very shiny”).

• In some tests, photos are taken and assessed by blinded experts.

Benefits:

• Reflects real-life product performance.

• Combines visual impression with user experience (touch, softness, manageability).

• Can be paired with instrumental testing for full validation.

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