2001: A Sleeping Mat Odyssey: Through the end of the last century, outdoor enthusiasts relied on one of two types of sleeping mats: thin closed-cell foam mats or slightly thicker self-inflating mats. Both provided some level of comfort and insulation from the cold hard ground, but neither did so with great effect. In 2001, EXPED introduced a revolutionary product - the DownMat – which created an entirely new category of sleeping mats – much warmer, lighter and more compact than previous mats. This new category necessitated a means of measuring and comparing the efficiency of the insulation, so we pioneered the use of R-value testing to determine the “warmth” of a sleeping mat. Almost 20 years later the outdoor gear companies have agreed upon an international standard method for testing the R-value of sleeping mats, based heavily on EXPED’s previous work with EMPA, the Swiss Federal Laboratories for Materials Science and Technology.