VF Corporation

VF Corporation

The science of better socks


Plenty of apparel brands use Merino wool, but Smartwool’s approach is different. It knows that it’s not just about the wool, it’s about what you do with it. Smartwool, part of VF Corporation, wanted to take sock design to the next level. Innovia helped it to understand how feet react in different climates, and how socks affect – and are affected by – these physiological changes.


We designed experiments to test how feet respond to exercise in hot and cold environments and turned raw thermographic data into maps. The maps clearly communicated how men’s and women’s feet heat and cool in these environments, and showed how the observable changes related to the underlying physiology.

We then tested how feet sweated in three different types of running sock. This involved carefully designing the experiments to minimise random variations and maximise the chances of measuring a small effect. After analysing the results, we showed that there was a statistically significant difference between one type of sock and the other two, and showed Smartwool the physiological implications for blister formation. As well as running and sweating, our test subjects filled out a questionnaire about their preferences. This led to the interesting discovery that one particular aspect of sock design is very polarising.


Our work helps Smartwool to stay true to its promise of using Merino wool as cleverly as possible. Smartwool’s designers can look at Innovia’s maps to help them design socks that are tailored to the physiology of men and women: using Merino wool in the right ways to help them stay warm in the cold, and cool in the heat – and dry and blister-free everywhere!

The image above left shows a thermograph of a female test subject’s feet after running. We used thermography to measure foot temperatures after running in different types of socks. The image above right shows the evolution of Smartwool’s socks from 1994 to 2016. Innovia’s work led into the design of the 2016 range of socks.