Viscosity

Viscosity is the measure of the thickness and density of a liquid or semi-fluid substance. The higher the viscosity, the thicker the substance. A product’s viscosity is defined by its resistance to flow and in skincare, an essential component of quality control. Specific viscosity is used for certain types of products to prove its effectiveness and to to satisfy the expectations of customers. For example, a lip balm has to be highly viscous in order to swipe on lips while a facial mist needs to be low in viscosity to spritz easily from the bottle. Then there are products like emulsions that are shear thinning (also referred to as pseudoplastic), meaning that its viscosity decreases with increasing shear rate and is a result of structural breakdown within a substance. When it comes to layering multiple skincare products, you should apply them from the thinnest to the thickest viscosity to reap the maximum benefits from each. This means after cleansing your face, apply a toner, serum and then cream. As you browse the aisles, look for words like "rich" or "luxurious" on your skincare to describe products that may have high viscosity, while words like "light" or "natural" are usually used to describe products with low viscosity.

The measure of the thickness and density of a liquid or semi-fluid substance. The higher the viscosity, the thicker the substance.