Abstract background of colorful painted water and oil

High Viscosity

Originally contributed by Jeff Butler • last updated 1/11/2021

If you think about how thick honey is compared to water, you can probably start to imagine how much slower it flows, as if its layers were working against each other to retain their shape. This thickness of a liquid, like honey or water, is typically measured in terms of its high viscosity.


Generally, the terms high viscosity and low viscosity refer to the thickness or thinness of a liquid. Typically, the thicker a liquid is, the more viscous it is (or the higher its viscosity is). In the same way, the thinner a liquid is, the less viscous it is (or the lower its viscosity). More technically, viscosity refers to a liquid’s resistance to flow or deformation — in essence, its resistance to change. Conceptually, viscosity can be thought of as the result of the friction between the layers of a liquid as it moves.

What Is Viscosity Used For?

Viscosity isn’t a word that gets used often but there are times when knowing how to use it could come in very handy. For example:

  • The viscosity of paints and finishes may determine how easily they can be applied with different tools, such as brushes, rollers, and sprayers. If a paint or finish has a high viscosity, it will generally be harder to spread over a surface.
  • Viscosity is also a word that gets used to describe the thickness of engine oils for equipment, like lawn mowers and snow blowers. Oils with less viscosity typically reduce the amount of friction in an engine, allowing parts to move easier, especially in colder weather.