All breathable, waterproof fabrics in the outdoor industry are measured, evaluated, and compared on the basis of their moisture vapor transmission rate or MVTR. Alpine jackets, storm pants, and breathable waders all have a lab-tested MVTR which is often tested using a one-inch-square swatch of fabric. In real life, however, we perspire more in some areas more than others. In waders, moisture most often builds up in your crotch and lower back, but not so much along your shins.
What this means is that no matter how breathable a small patch of your wader membrane may be, moisture vapor may be log-jammed in some areas, and nonexistent in other areas. To make the whole garment work effectively, the moisture should be distributed evenly as possible, and that's the idea behind the new Redington Super Dry Fly waders constructed with a Cocona-brand lining.
Cocona uses natural micro-particles embedded in polyester fibers to increase performance by actively moving moisture away from your skin and distributing it across the inside surface area of the wader so it can quickly pass through the breathable membrane—and the entire wader becomes more breathable in the process. A byproduct of the design is that the base element used by Cocona comes from coconut husks, which is naturally odor-resistant and fast-drying.
Redington (redington.com) has designed three new waders with the Cocona lining and sonic-welded seams, a wading jacket, and a full line of baselayers using the fabric, all available by February 2014. For more information see the video below.