Quantifying Nail Varnish Drying Using a THz Vector Network Analyser

Nail varnish and its drying properties are explored in detail using a terahertz vector network analyser in a quasioptical transmission configuration. Assessing the `dryness' of nail varnish through the measurement of transmitted terahertz radiation, as opposed to qualitative, and typically touch-based techniques, takes into account the non-uniform drying of the nail varnish as a function of its depth. This method can be used to assess the actual dryness of the layer overall and offer measurable parameters to quantify the drying properties of each mixture.