Curl Droop Testing
The most commonly used evaluation technique for style longevity involves some version of a high humidity curl droop experiment. Elevated humidity represents especially torturous conditions, so longevity experiments are frequently performed at this challenging state.
Products are applied to hair tresses which are set in a given confirmation using a pegboard. After drying and equilibration at low humidity, tresses are removed and hung upright – where the length of the tress is then quantified as a function of time after raising the relative humidity. Testing is performed on multiple tresses to ensure statistical rigor.